Nested Bean Zen Sack®- Gently Weighted Sleep Sacks | Baby 15-24M | TOG 0.5 | 100% Cotton | Aids Self-Soothing | 2-Way Zipper | Machine Washable Baby 15-24 Months Weight: 26-36lbs; Length: 31-38in The Zen Sack Classic provides gentle pressure that mimics your reassuring embrace where babies are naturally held. This creates a secure feeling for babies that prevents wakeups from sleep regressions and facilitates self-soothing, resulting in deeper periods of sleep. Special features. A gently weighted Cuddle Pad soothes like your embrace. Adjustable snaps grow with your baby and a top-quality 2-way zipper ensures easy changes. The Zen Sack can be worn backwards during sleep by babies rolling independently. Adjustable snaps grow with your baby, so your sleep sack lasts longer! Highest-quality, OEKO-TEX-tested 2-way zipper makes nighttime changes a breeze with Zen Sack.