Hudson Baby soft, breathable cotton muslin sleeping bag is perfect for your little infant while sleeping. Our sleeping bag is sleeveless and has an inverted zipper for easy on and off dressing and diaper changes. This is the perfect solution to keep baby warm during the cooler nights with two layers of soft muslin cotton, but still allows baby's skin to breathe. Size 0-6 Months fits baby from 10-18 lbs and about 23-26 Inches in height. Size 6-12 Months fits baby from 15-24 lbs and about 26-31 inches in height. Size 12-18 fits baby 22-28 lbs and about 30-34 inches in height. Size 18-24 Months fits baby 26-36 lbs and about 35-38 inches in height. Hudson Baby Infant Boy Muslin Cotton Sleeveless Wearable Sleeping Bag, Sack, Blanket, Blue Whale is the perfect addition to your little one's nursery. Our sleep sacks, wearable blankets and sleeping bags are always intended to be worn over children's sleepwear.