Your baby sleeps better in your embrace or with your palm on their chest.The Zen Sack simulates the pressure from your touch with a lightly weighted pad and plush upper panel on their chest. Parents who’ve used it report their babies fall asleep easier and stay asleep longer within 1 to 3 nights.70% Rayon from Bamboo, 30% pure Cotton. Adjustable shoulder tabs allow for a better fit and room for growth. The two-way zipper system makes diaper changes a breeze. Naturally antimicrobial & thermal regulating.