Changing a crib has never been easier! From Basic Comfort, the "Ultimate Crib Sheet" is really 4 products in one: a quick change sheet, a mattress pad, a super absorbent pad, and a waterproof pad. To use, just snap the crib sheet onto the crib bar and it will remain firmly in place. As an added safety feature, two straps are included for fastening around the springs or slats underneath the mattress. The sheet itself consists of a polyester/cotton top, an absorbent polyester/rayon middle layer, and a 100% vinyl backing. Fits all standard cribs. Measures 52" x 28". Machine washable.