Polyester Cover Only - Foam elevator not included. Optional covers are poly/cotton; includes velcro strap and fitted sheet type fit, easy to remove and install for machine washing. Designed for Mattress elevator 7" height, but will also work with the 5" height version as well. Avana Mattress Elevator, Provides A 7” To 1” Incline Down The Full Length Of The Bed.Foam Bed Riser That Provides A Safe And Drug-free solution that can naturally help with symptoms of Acid Reflux, GERD (gastroesophageal reflux disease), snoring, or sinus issues through elevation Install Avana Mattress Elevator Under The Mattress And Enjoy The Full Comfort, Width, And Length Of Your Original Mattress. Twin Size Supplied As One Solid Piece. The Full-bed-length provides additional mattress stability and support. (foam elevator sold separately) Twin Size Supplied As One Poly/Cotton Cover. Measures 39" X 74" - the size of a complete twin bed Includes manufacturer guarantee