Sleep tight is a patented product designed to help children sleep undressed during the night. it also helps prevent children from falling out of bed on beds without a railing. it is easy to use thanks to the double-sided zipper sewn into the flexible fabrics on the sides of the duvet cover. it is 100% cotton fabric. set contents1 duvet cover1 fitted sheet1 35 x 55 pillowcases1 50 x 70 pillowcases it is recommended to be used with a 90 x 170 duvet. washing at 30 degrees is suitable. drying is not recommended. Improved version for clearer understanding and better search visibility. Suitable for users seeking detailed and reliable product information.