Will it off-gas or smell when delivered?

Expect only a faint, short-lived foam scent. At 13 inches this is the thickest model with a 2-inch dual comfort layer, yet it still clears off-gassing in under 12 hours for a 9-out-of-10 score, because it ships uncompressed and flat rather than vacuum-rolled. The foams hold CertiPUR-US certification against strict VOC limits. Unzip it in an aired room and the smell is essentially gone by the next evening, ready to sleep on.