Customize Bed by Fortnight Bedding''s vinyl covered memory foam mattress was created with a luxurious foam that retains its shape throughout the night. This 4 inch memory foam mattress is the size of a standard twin size mattress and is infused with our special engineered gel for temperature control and comfort. Our foam is always made in the US and is CertiPur-US certified so it contains no PBDEs, TDCPP or TCEP ("Tris") flame retardants, ozone depleters, mercury, formaldehyde, lead and heavy metals. Why Vinyl? Sleeping through the night with a piece of mind, knowing that your allergies will not act up, is another benefit of sleeping on a vinyl covered mattress. A vinyl mattress also aids in the longevity of your mattress, because it is the best protection. It is a perfect solution for overnight guests, potty training, and camping because of how easily the mattress cover can be cleaned. Before Ordering: Please be sure to accurately measure your bed frame to ensure your new mattress fits perfectly. The firm structure of our high-density foam mattresses is perfect for those with a heavier build. We recommend that those who have a heavier build purchase our 4 or 5 inch mattress to ensure a rested and comfortable sleep. Setup: Mattress comes conveniently right to your door in a box! They are compressed and rolled in a box so it''s easy to transport and set up. After your mattress arrives, simply remove it from the box and remove the plastic, being careful not to cut into the mattress. Allow 24-48 hours for your new mattress to decompress and return to its original shape.