The Elephants Fresh Air Crib Liner is 12 inches high and fits a standard size, 28 inch x 52 inch crib interior. It provides fresh air flow for a better sleep and keeps arms and legs inside crib. It's unique design keeps it in place for easy sheet changes and eliminates sagging. The shell of the crib liner is made of 100% cotton. The mesh is 90% nylon and 10% spandex. The platform is 65% polyester and 35% cotton. Filling is 100% polyester. Care instructions: close all zippers and fasteners before washing, do NOT wash with delicate fabrics, machine wash cold in gentle cycle, use only NON-chlorine bleach when needed, tumble dry low, do NOT iron.