Polyester Blend,cotton Imported Soft & Comfortable Fabric: Crafted from a high-quality cotton-polyester blend, this fitted nap/rest mat sheet adds a soft, breathable layer of comfort and warmth to daycare and preschool mats. Perfect Fit for Standard Nap/Rest Mats: Measuring 24" x 48" x 4", this sheet is designed to fit folding nap/rest mats up to 2" thick. Pre-washed to reduce shrinkage and ensure a consistent fit after washing. Secure, Comfortable Fit with Elastic Corners: Features four durable elastic corners that easily stretch over nap/rest mats, holding the sheet securely in place. Provides a snug fit and added comfort to help children rest better. Secure, Comfortable Fit with Elastic Corners: Features four durable elastic corners that easily stretch over nap/rest mats, holding the sheet securely in place. Provides a snug fit and added comfort to help children rest better. Enhances Comfort & Cleanliness at Nap Time: Add an extra layer of coziness to any nap/rest mat while helping maintain a clean and hygienic nap environment. A great addition to any daycare or classroom setting.