HALO's 100% cotton SleepSack wearable blanket in the Midnight Moons Blue print replaces loose blankets in the crib, keeping baby cozy without loose bedding that can cover the face. The sleeveless design helps reduce overheating, and the inverted zipper opens from the bottom for easy diaper changes. Signature Back is Best embroidery is a gentle reminder to place baby on the back to sleep. The roomy sack design is recognized as Hip Healthy by the International Hip Dysplasia Institute. Made from 100% cotton interlock with a TOG 0.5 rating for warmer rooms. Wear over regular sleepwear; machine wash with like colors.