The patented two piece QuickZip sheet set is designed to be simple, safe and stylish. The top zips off the base for easy changing. No more mattress wrestling or constant tying and untying of bumper ribbons. Unlike loose fitting sheets that can cause an entanglement danger to your baby, QuickZip fits snugly around your mattress. And since we preshrink all our fabrics, our sheets fit wash after wash. The starter set includes one zipper base and one zipper top. Most customers buy an additional zipper top for convenience, as well as our soft, waterproof mattress pad for comfort and protection. Buy a set for you, one for the babysitter and one for grandma. Hands down, QuickZip sheets are the best baby shower gift for any parent.