Carters flat crib pads provides extra absorbency and comfort for all your waterproofing needs. Place the pad under your fitted sheet in cribs and toddler beds, play yard, porta crib for extra waterproof protection. 100% waterproof back protects mattresses from accidents. Fits on top of standard crib mattress (28" x 52"). 100% Waterproof Fabric with Cotton Flannel Surface / Machine washable. Perfect baby basic every nursery needs.