Home

OPEN BAG - NM 12″ Medium Firm Memory Foam Mattress - King

Meet NM® Cozy Memory Foam—all‑foam mattresses that pair cooling, temperature‑regulating comfort with low motion transfer, pressure‑point relief, and reinforced edge support. Thoughtful touches include hypoallergenic care, eco‑friendly manufacturing, adjustable‑base compatibility, and mattress‑in‑a‑box convenience.

Top Features

Add To Compare

– Optimal High Resilient Bio-Foam Core

– Gel Infused Visco Memory Foam

– Cotton Channel Quilted Cover

– 10 Year Warranty

– Made In Toronto, Canada

Our Price: $967.00

$773.60

Retail Price $1,799.00

In stock

Only 2 left

Boxspring

Without Boxspring

Mix-Match Boxspring

Matching Boxspring

Options

Standard 8" + $220.00

Low Profile 4" + $220.00

Platform 2" + $220.00

Options

High Profile 8" + $250.00

Low Profile 4" + $250.00

Qty

Applicable Offers

+ Get 15% OFF any Sleep Accessories Bundle with the purchase of any mattress.

+ Become a VIP MEMBER and SAVE even more on your mattress purchase!

➜ A portion of every sale supports the Sleeping Children Around The World (SCAW) Foundation. Click here to learn more.

Our Guarantees

+ Learn More About Open Bag items

+ Full Manufacturer’s Warranty

+ Price Match Guarantee

+ Made in Canada

➜ Not sure which mattress is best for you? Try our MATTRESS SELECTOR to help you decide!

➜ See our REVIEWS from verified customers!

OPEN BAG - NM 12″ Medium Firm Memory Foam Mattress - King

Skip to the end of the images gallery

Memory Foam, Foam Core/No Coils, King Size Mattress, NM Mattress Sale, Buy in Toronto, Mississauga, Markham or Online-1

Memory Foam, Foam Core/No Coils, King Size Mattress, NM Mattress Sale, Buy in Toronto, Mississauga, Markham or Online-2

Memory Foam, Foam Core/No Coils, King Size Mattress, NM Mattress Sale, Buy in Toronto, Mississauga, Markham or Online-3

Memory Foam, Foam Core/No Coils, King Size Mattress, NM Mattress Sale, Buy in Toronto, Mississauga, Markham or Online-4

Memory Foam, Foam Core/No Coils, King Size Mattress, NM Mattress Sale, Buy in Toronto, Mississauga, Markham or Online-5

Memory Foam, Foam Core/No Coils, King Size Mattress, NM Mattress Sale, Buy in Toronto, Mississauga, Markham or Online-6

Skip to the beginning of the images gallery

Style	Memory Foam, Foam Core/No Coils
Firmness	Medium
Coil Count	N/A
Coil Type	N/A
Core Type	NM® HD+™ High Density Support Core
Core Density	1.8 lb/ft³
Height	12 Inches

Collection	NM® Cozy
Model	Chelsea CoolMax Pro Advanced 12" - King
Warranty	10 Year Warranty
Condition	Open Bag Item - Clearance

Comfort Scale

Soft
Medium
Firm
Extra Firm

Comfort IQ™: This mattress is slightly softer compared to other medium-firm mattresses. (4/10)

Recommended For: Side Sleepers, Back Sleepers, Stomach Sleepers

Our Guarantees

+ Learn More About Open Bag items

+ Full Manufacturer’s Warranty

+ Price Match Guarantee

+ Made in Canada

➜ Not sure which mattress is best for you? Try our MATTRESS SELECTOR to help you decide!

➜ See our REVIEWS from verified customers!

Description

Open Bag - NM 12" Medium Firm Memory Foam Mattress - King: Discover Unmatched Comfort for Restful Sleep!

Transform your nightly routine with the NM 12" Medium Firm Memory Foam Mattress—a perfect blend of luxurious comfort and vital support. Built with advanced sleep technology, it caters to every sleep position, cradling your body while ensuring proper spinal alignment. Embrace the ultimate sleep experience where plush comfort meets revitalizing support, allowing you to recharge and face each day with renewed vitality!

Key Features

High Resilient Bio-Foam Core: Feel the difference with our premium bio-foam core that adapts to your body’s contours, providing exceptional support and alleviating pressure points for a rejuvenating sleep.
Cooling Gel Memory Foam: Experience refreshing nights with our gel-infused memory foam that disperses heat, keeping your sleep space comfortably cool while you drift into a deep slumber.
Breathable Cotton Cover: The soft cotton quilted cover promotes airflow, offering a cushy yet relaxing surface for a cozy sleep environment any time of the year.
Medium Firm Feel: Combining plushness with essential support, this mattress accommodates side, back, and stomach sleepers, ensuring optimal comfort and alignment all night long.
Crafted in Toronto, Canada: Each mattress reflects quality craftsmanship, proudly supporting local manufacturing while providing you with a product that embodies excellence.

Benefits

Cool and Comfortable Nights: Our innovative cooling technologies help maintain a comfortable temperature, so you can enjoy uninterrupted sleep, waking up revitalized each morning.
Long-Term Assurance: Rest easy with a 10-year warranty, guarding your investment while you indulge in countless nights of blissful rest.
Convenient Delivery: The NM mattress is delivered boxed and rolled, facilitating easy transport and quick setup for an effortless transition to better sleep.

Ideal For

This mattress is an excellent choice for anyone who values craftsmanship and comfort in their sleep experience. Whether you are a side sleeper who loves softness or a back sleeper in need of support, it effortlessly adjusts to fulfill your specific sleeping needs. Perfect for those in Toronto and beyond, enjoy a restful retreat each night.

Details

Dimensions: 76" x 80" (inches), 193cm x 203cm (centimeters)
Profile Height: 12 Inches
Firmness Rating: Medium
Warranty: 10 Year Warranty
Guarantees: Includes free next day delivery, 100 night sleep trial, full manufacturer's warranty, and price match guarantee
Certifications: Foam materials are CertiPUR-US certified
Cover Material: Soft, luxurious cotton cover that is removable and features a non-skid bottom
Core Composition: Two comfort layers—2.5″ Gel Infused Visco Memory Foam and 2″ High Compression Bio-Foam, topped with 1.8lbs Pressure Relieving Comfort Foam

Choose the NM 12" Medium Firm Memory Foam Mattress for a sleep experience that seamlessly marries quality, innovation, and unparalleled comfort, inviting you to enjoy tranquil nights and invigorating mornings every day!

Specifications

More Information
Mattress Size	King
Mattress Type	Memory Foam , Foam Core/No Coils
Features	Cooling Technology , Temperature Regulating, Low Motion Transfer, Pressure Point Relief, Edge Support, Hypoallergenic, Eco-Friendly Manufacturing, Compatible with Adjustable Bed Base, Mattress In A Box
Trending & Offers	Clearance , Limited Stock
Firmness	Medium
Core Type	NM® HD+™ High Density Support Core
Core Density	1.8 lb/ft³
Core Material	Polyurethane (polyfoam)
Brands	NM
Price Range	Great Value
Model	Chelsea CoolMax Pro Advanced 12" - King
Collection	NM® Cozy
Condition	Open Bag Item - Clearance
Warranty	10 Year Warranty
Sleep Position	Side Sleepers, Back Sleepers, Stomach Sleepers
Cover Material	SoftLux Breathable Cotton
Colour	White, Grey
Quilt	0.5″ Cotton Channel Quilted Cover
Comfort Layers	2.5″ Gel Infused Visco Memory Foam, 2″ High Compression Bio-Foam
Support Layers	1.8lbs Pressure Relieving Comfort Foam, 2.5″ Supersoft High Density Foam
Mattress Core	5″ Optimal High Resilient Bio-Foam
Mattress Height in Inches	12 .00 Inches
Additional Features	Available boxed and rolled for easy shipping and handling.
Certifications	CertiPUR-US® certified foams.
Compatible With Adjustable Beds	Yes
Vented	Yes
Removable Cover	Yes
Handles	No
Care Instruction	Removable cover, dry clean to prevent shrinking.
Country of Origin	Canada
King Size Dimensions	76″ x 80″ (inches) – 193cm x 203cm (centimeters)
Custom Sizes Available	Yes
Product Length (inches)	80 in
Product Width (inches)	76 in
Product Height (inches)	12 in
Product Weight (lb)	145.000000
Product Length (cm)	203.2 cm
Product Width (cm)	193 cm
Product Height (cm)	30.5 cm
Product Weight (kg)	65.8 kg
Product Barcode	628719062913
Product Model Code	NM-CHELSEA
Product SKU	NM-CHELSEA-KING-OPENBAG
Product Category	Mattress
Product Sub Category Tier	Value
Product Type	Mattress - Foam Core
Product Sub Type	Memory Foam

More Info.

NM Brand Mattresses

Exceptional Comfort. Locally Crafted. Unmatched Value.

At NM, we believe everyone deserves a great night's sleep without overspending. That's why our NM Brand mattresses are proudly manufactured locally, ensuring exceptional quality and unbeatable prices you simply won't find anywhere else.

Premium Quality, Affordable Prices

Each NM mattress is thoughtfully crafted with premium materials and meticulous attention to detail, delivering outstanding comfort and support for every sleeper. By partnering directly with trusted local manufacturers, we eliminate unnecessary markups and bring you unmatched value.

Designed for Every Budget and Preference

Whether you prefer a firm mattress for optimal support, a plush surface for luxurious comfort, or something perfectly balanced, NM has the right mattress for your needs. Our wide range ensures you'll find the perfect match without stretching your budget.

Why Choose NM Brand?

Locally Manufactured: Supporting Canadian craftsmanship and quality control.
Superior Value: High-quality mattresses at unbeatable prices.
Variety and Versatility: Comfort options to suit every sleep preference and budget.
Durable and Reliable: Built to provide lasting comfort night after night.

Discover the NM difference—affordable, comfortable sleep that's locally crafted for your best night's rest.

Delivery Options

Greater Toronto Area and Ontario Delivery Map

What’s Included

We offer FREE DELIVERY to all major cities in Ontario and the surrounding area on orders over $199. A delivery surcharge of $45 applies to orders under $199.

Select your delivery date at checkout (if applicable) and add any special instructions in the order comments (e.g., “Ring Buzzer #1234”). If a date isn’t shown or selected at checkout, you’ll receive an email with scheduling options. Day‑of, you’ll get a text and email with a 2‑hour window and live tracking. Estimates apply to in‑stock items; rural or weather‑affected addresses may require extra time.

Greater Toronto Area and Ontario Free Mattress Delivery Map

Ontario Local Delivery Areas

Next‑day available

Halton Region

Burlington • Oakville • Milton • Georgetown • Halton Hills

Next‑day available

Peel Region

Mississauga • Brampton • Caledon

Next‑day available

City of Toronto

York • Including Downtown Core

Next‑day available

York Region

Vaughan • King • Richmond Hill • North York • Aurora • Newmarket • Markham • Scarborough

Next‑day available

Durham Region

Pickering • Ajax • Whitby • Oshawa • Whitchurch‑Stouffville

Next‑day available

Waterloo Region

Guelph • Kitchener • Cambridge • Waterloo

Next‑day available

Hamilton

Including Dundas • Grimsby • Stoney Creek • Ancaster

1–3 days on average

Niagara

Niagara Falls • Niagara‑on‑the‑Lake • St. Catharines • Thorold • Welland

Next‑day & 1–3 days

Simcoe Region

Barrie • Innisfil • Orillia • Midland • Collingwood • Bradford • Washago and more

1–3 days on average

Northern &
Eastern Ontario

Cobourg • Peterborough • Kawartha Lakes • Minden • Haliburton • Port Perry • Bowmanville and more

1–3 days on average

Western Ontario

London • Stratford • Woodstock • Brantford • Grand Bend • Port Elgin • Tobermory and more

Need delivery outside the GTA?

We also ship to all provinces in Canada at competitive rates (territories excluded). Enter your postal code at the top of the website to see what’s available.

Ready to Sleep Better?

Shop online 24/7 or visit any National Mattress location across Ontario. Spend $199+ and relax—your new mattress will arrive quickly and free of charge locally, or ship fast across Canada.

Shop Mattresses

Frequently Asked Questions

Where does National Mattress offer free local delivery?

We offer FREE local delivery to major cities across Ontario on orders of $199+. Check the region cards above for specific cities.

Do you ship mattresses across Canada?

Yes. We ship select roll‑packed mattresses to all provinces (YT, NT, NU excluded). Transit times range from 1–2 days in ON & QC to 3–4 days in BC and NL after shipping.

Is next‑day delivery available in the GTA?

Yes. FREE next‑day local delivery is available in many GTA and surrounding areas, subject to inventory and cutoff times.

What if my Ontario local order total is under $199?

A $45 delivery surcharge applies to orders under $199.

How do I schedule or change my delivery date?

Select a date at checkout. If a chosen date isn’t available, you’ll receive an email proposing an alternative—simply reply to reschedule. In‑store purchases can be scheduled at the time of sale.

Will I get tracking updates?

Yes. Local deliveries include day‑of text/e‑mail with a 2‑hour window plus live GPS tracking. Canada‑wide shipments include a courier tracking number once picked up.

Do you deliver to Yukon, Nunavut, or the Northwest Territories?

No. We currently do not deliver to YT, NU, or NT.

Need help? 1‑800‑631‑4883 [email protected]

Product Questions (31)

Customer Questions

How long should I wait before sleeping on this mattress after unboxing?

This mattress can usually be slept on the same day you unbox it, but it may take up to 24-72 hours to reach its full height and intended feel. Consult the product instructions for specific recommendations on minimum expansion time before regular use...

What are the box dimensions and weight for this mattress?

The box dimensions and weight for this mattress in a box are listed in the delivery details section. Review them to ensure you can move the box safely into your room, and consider having an extra person help for larger sizes.

Is this memory foam mattress suitable for side, back, or stomach sleepers?

This memory foam mattress has a specific firmness and layering profile that will suit some sleep positions better than others. Check the comfort description and any recommended sleep positions in the product details to see whether it is best for side...

Is this memory foam mattress suitable for couples with different comfort preferences?

This memory foam mattress is designed with a balanced comfort and support profile that many sleepers find comfortable, but it may still favor certain preferences. Review the firmness level, motion isolation information, and customer feedback to see ...

What warranty and trial period come with this mattress?

Yes, we offer a 100 night sleep trial with any mattress purchase.

How does this mattress compare in value to your conventional models?

This eco-friendly mattress offers a combination of sustainable materials, cleaner manufacturing, and comfort features that may justify its price compared to conventional models. Compare its construction, certifications, expected lifespan, and cost with...

Is this king mattress good for side sleepers?

Side sleepers usually prefer a mattress that relieves pressure at the shoulders and hips while keeping the spine aligned. Look for king mattresses described as medium or medium-soft with comfort layers that contour to the body and cushion key pressure...

How does this mattress help guard against dust mites and other allergens?

This mattress incorporates features such as tightly woven or treated covers, dense core materials, and/or breathable construction to help reduce dust mite and allergen buildup. See the product description for details on the specific anti-allergen strategies...

Is this foam mattress better suited for a primary bedroom or a guest room?

This mattress offers a specific combination of comfort, support, and durability that may make it ideal for nightly use in a primary bedroom. Review the firmness, build quality, and price point to decide where it best fits in your home.

Is this mattress designed to reduce motion transfer?

Yes, this mattress is specifically designed with materials and construction that help reduce motion transfer across the bed. Check the construction and materials section for details on the foams, coils, or layering that contribute to its motion isolation...

Can this king mattress be used on a storage bed or platform bed?

Most king mattresses are compatible with platform and storage beds as long as the base provides adequate, even support. Check the product details for any specific base recommendations and ensure your frame's slats or platform are sturdy and properly...

Do I need a mattress protector for this memory foam mattress?

A mattress protector is strongly recommended for any memory foam mattress. It helps keep the surface clean, protects against spills and allergens, and can extend the life of the mattress by preventing moisture and debris from breaking down the foam ...

Is this mattress recyclable or made with recyclable components?

This eco-friendly mattress includes components such as steel coils or certain textiles that may be recyclable, and uses materials chosen to reduce environmental impact at end-of-life. Check the product details or brand information for guidance on responsible...

Will this mattress hold its shape and pressure-relieving feel over time?

This pressure-relief mattress is built with comfort and support materials selected to maintain their feel under normal use. Review the durability details, foam densities or coil specifications, and care recommendations in the product description to ...

Will this mattress maintain its shape and support over time?

This mattress in a box is built with materials selected to maintain their shape and support under normal use. Review the durability information, foam densities or coil specs, and care recommendations on the product page for guidance on its expected ...

Is this mattress available in sizes suitable for both single and coupled back sleepers?

This mattress is available in a range of sizes, from Twin or Twin XL for single sleepers up to Queen and King for couples. Choose the size that best fits your sleeping arrangements and bedroom layout.

Is this mattress suitable for my specific allergies or sensitivities?

This mattress is designed to reduce common allergens, but individual sensitivities can vary. Check the full materials list and any allergy-related claims, and consult with your healthcare provider if you have specific allergies (like latex or wool) ...

How does this mattress compare to your other models for allergy-friendly features?

This hypoallergenic mattress emphasizes reduced allergen buildup and low-emission materials within our lineup. Compare its construction, certifications, and customer feedback with our other models to determine which one offers the best combination of...

Does this memory foam mattress have cooling features?

This memory foam mattress incorporates materials and design elements such as gel-infused or open-cell memory foam and breathable cover fabrics intended to help manage heat. Check the product description for specific cooling technologies included in ...

What warranty and trial period apply when this mattress is used on an adjustable base?

Yes, we offer a 100 night sleep trial with any mattress purchase.

Will this foam mattress support my lower back properly?

This foam mattress is designed to provide a balance of contouring and support through its layered foam construction. Check the firmness rating and any notes about zoned support or targeted lumbar support in the product description to ensure it aligns...

Is this mattress a good choice if my partner and I have different builds?

This medium-firm mattress is designed to offer a balanced feel that can work for a range of body types. If there is a large difference in weight or preferences, review the support specs (coil system, foam density, or zones) and customer reviews to see...

Is this king mattress comfortable for everyday use?

This king mattress is designed for regular nightly use with a balance of comfort and support suitable for its intended sleeper group (such as couples, families who co-sleep, or single adults who want extra space). Check the firmness level, materials...

Can this mattress be used as my primary bed for the long term?

Yes, this mattress in a box is designed for regular nightly use when matched with the right base and care. Review the durability details, warranty coverage, and recommended maintenance practices to see how it is intended to perform as a long-term primary...

Is this foam mattress suitable for side, back, or stomach sleepers?

This foam mattress has a specific firmness and layering profile that will suit some sleep positions better than others. Check the comfort description and any recommended sleep positions listed in the product details to see whether it is best for side...

Does this king mattress come rolled or boxed?

Many modern king mattresses are shipped compressed and rolled in a box for easier delivery and setup. Check the product details for packaging information and follow the unboxing instructions to allow the mattress to expand to its full size.

Is this king mattress compatible with an adjustable base?

Many foam and hybrid king mattresses are compatible with adjustable bases and are designed to bend and flex as the base moves. Check the product description for specific notes on adjustable base compatibility and follow the manufacturer's guidelines...

Is this mattress considered hypoallergenic?

Yes, this mattress is designed with hypoallergenic features such as dust mite-resistant materials, breathable construction, and/or reduced use of common irritants. Check the construction and materials section for details on the specific hypoallergenic...

How long does it take for a king mattress to fully expand after unboxing?

Most boxed king mattresses expand to near full size within a few hours, but they may continue to relax and reach their final feel over 24-72 hours. Room temperature, ventilation, and the specific materials can affect expansion time; follow the manufacturer...

Is this memory foam mattress better suited for a primary bedroom or a guest room?

Do I need a mattress protector for this foam mattress?

A mattress protector is strongly recommended for any foam mattress. It helps keep the surface clean, protects against spills and allergens, and can extend the life of the mattress by preventing moisture and debris from breaking down the foam layers ...

Did you find what you were looking for?

Your question:

Your name:

get notification on email when the answer is ready

Your e-mail: