"The -2.5-Gel-Infused-Memory-Foam-Mattress-Topper arrived quickly and then was unpacked at my son's new  furnished apartment at ASU.  There was no smell and I have a sensitive smeller. It puffed out immediately and covered the mattress fully. We made the bed without waiting 24 hours along with these other products from Wayfair: Bed-in-a-bag set, Sleep Tite down alternative mattress pad, and a Bed Blocker Mattress Protector to cover the existing mattress. These were all ordered in Full Size. Good thing because the mattress provided in the apartment was on box frame with drawers under it and the mattress has no cushion.  These products all fit perfectly and he says his bed is very comfortable and gets a good nights sleep. "