Hudson Baby Safe Sleep Fleece Wearable Sleeping Bag Blanket 2-Packs are perfect for cold nights. Your babe will be snug and safe in this sleeveless wearable blanket. To make diaper changes easier, we've designed this sleeping bag to have an inverted zipper. Made of polyester fleece, this sleeping bag is cozy warm and soft! To prevent SIDS, it is recommended that a baby does not have any blankets or toys in the crib. To keep baby warm, the Hudson Baby fleece wearable sleeping bag blanket is the perfect affordable sleep option. This sleeping bag is also looser at the hips than a velcro swaddle blanket which allows hips and legs to move freely to help prevent any hip dysplasia. Size 0-6 Months fits 10-18 lbs, Size 6-12 Months fits 15-24 lbs, Size 12-18 Months fits 22-28 lbs, Size18-24 Months fits 26-36 lbs.