Sleep Innovations 2 inch Memory Foam Mattress Topper and Waterproof Mattress Pad – Twin XL Price: $89.99 (as of 18/10/2017 13:01 PST- Details)

Premium memory foam makes any mattress more comfortable and like new
Includes Dreamaway Waterproof padded cover for comfortable, hypoallergenic protection
Custom-fit cover keeps topper in place (Fits up to 15-inch deep mattress)