100% Cotton WEARABLE BLANKET - for safer sleep. Keeps them cozy and can’t be kicked off SEAMLESS TRANSITION - recommended after HALO SleepSack swaddle for less sleep interruption EASY DIAPER CHANGES - with zipper that opens from bottom. Zipper cover at neckline prevents scratches. EXTRA LENGTH - get more wear without sizing up as quickly HIP-HEALTHY - approved by the International Hip Dysplasia institute for healthy hip development Size Large (12-18M)