The SwaddleDesigns Transitional Swaddle Sack is designed to help babies transition from a traditional swaddle to a wearable blanket. It features arms up half-length sleeves and foldover mitten cuffs that can be worn open or closed, allowing babies to self-soothe and sleep better. The snug fitting and hip-healthy design supports the baby in a natural position, providing a sense of security. Made from 100% soft, stretchy cotton knit with a TOG rating of 0.7, it includes a 2-way zipper for easy diaper changes. Ideal for babies who prefer to sleep with arms up, are starting to roll over, or can break out of a traditional swaddle.