Cotton SAFE SLEEP MADE SIMPLE: Designed to keep your baby cozy and secure without loose blankets, it aligns with the American Academy of Pediatrics’ guidelines for safe sleep. HALO wearable blankets stay in place all night long, preventing your baby from kicking them off and waking up, so everyone enjoys uninterrupted sleep. CONVENIENT DIAPER ACCESS: Features a bottom-opening zipper for easy diaper changes, a comfy neckline with a zipper cover to prevent scratches, and an extra-long, roomy sack to support healthy hip development and reduce frequent sizing up. PREMIUM FABRIC FOR ULTIMATE COMFORT: Made from soft, breathable 100% cotton, this SleepSack is gentle on delicate skin, perfect for layering over regular sleepwear, and machine washable for easy care. TOG RATING 0.5 (room temperature 75°- 72°F): Ideal for hot summer nights or warmer climates, this lightweight option ensures breathability and keeps you cool and comfortable. HIP-HEALTHY: Approved by the International Hip Dysplasia Institute, this wearable blanket promotes healthy hip positioning. AVAILABLE IN 4 SIZES: Newborn (0-3 Months), Small (0-6 Months), Medium (6-12 Months), Large (12-18 Months), X-Large (18-24 Months) Today, HALO SleepSack Wearable Blankets are the #1 trusted choice of hospitals and are used to help babies sleep safely from the start. In addition to sleeping safer, it helps babies sleep better, too. It's a cuddly blanket they can't kick off; ensuring baby sleeps soundly throughout the night, with a unique, roomy sack design recognized by the International Hip Dysplasia Institute as "hip healthy." Inverted zipper opens from the bottom for easy diaper changes; sleeveless to reduce the risk of overheating; arm and neck openings sized for a safer fit.