Polyester,Cotton Imported EASY TRANSITION SLEEP SACK FOR BABIES: Helps your baby smoothly move from swaddling to a wearable blanket, with lightly structured arms that reduce startle reflex while promoting safer, more independent sleep. 100% SOFT COTTON & BREATHABLE FABRIC: Made from gentle, breathable cotton to help regulate temperature and keep your baby comfortable all night long, ideal for everyday use as a baby sleep sack. SAFER ALTERNATIVE TO LOOSE BLANKETS: This wearable blanket replaces loose bedding in the crib, supporting safe sleep practices recommended for infants and giving parents peace of mind. CONVENIENT 2-WAY ZIPPER FOR EASY CHANGES: Designed with a smooth, inverted zipper that allows quick diaper changes without fully removing the sleep sack, plus zipper covers for added comfort. HIP-HEALTHY DESIGN WITH MULTIPLE SIZES & COLORS: Designed with a roomy, ergonomic shape that supports healthy hip development while allowing natural movement, offered in Small (3–6 months) and Medium (6–9 months) sizes and available in heather pink, heather denim, and heather grey, machine washable. The Halo SleepSack Easy Transition helps control the Moro reflex for babies who no longer like to be swaddled, but still need a bit of security around the arms and torso. It is lightly quilted with sleeves and 4-way stretch cotton to help give your little one a snug, comforting fit without overheating; yet its roomy sack design supports continued healthy hip development. Snug upper-body design allows for easier post-swaddle transition to Halo's traditional SleepSacks for many babies.Made with two layers of super-soft knitted 100% cotton 4-way stretch fabrics lightly quilted with a polyester fill. TOG rating of 1.5 makes this perfect for moderate climates, seasons or environments and can be used over regular sleepwear to take the place of loose blankets. It is a warm and cuddly blanket your baby cannot kick off, ensuring that both you and Baby sleep soundly throughout the night.Available here in size Small for 3-6 month old babies who are generally 23-26 inches long, weighing from 13 to 20 pounds. 2-way zipper, with tab covers at top and bottom, allows for easy dressing and diaper changes.