Foot openings for mobility when awake Room to tuck in feet at night Use over regular sleepwear to take the place of loose blankets Unzips from the bottom for easy diaper changes. Generous sack design allows room for kicking, but cannot be kicked off so baby stays warm all night Sleeveless design reduces the risk of overheating "Back is Best" embroidery reminds caregivers to place baby on his or her back 100-Percent polyester micro-fleece