Halo's founder, Bill Schmid and his wife lost their first born to SIDS. From this tragedy, HALO and its mission were born. 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 warm 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. HALO donates a portion of every purchase to First Candle/SIDS Alliance and The Canadian Foundation for the Study of Infant Deaths. Made from 100% cotton interlock fabric with a TOG rating of 0.5, this Sleepsack offers just the right comfort for warmer seasons or climates, and can be layered with warmer sleepwear for cooler temperatures. Double knit construction of cotton interlock fabric makes it extremely soft and a little stretchy, perfect for baby sleepwear. Size Large is designed to fit babies weighing between 22 and 28 pounds, who are generally 12 to 18 months old and 30 to 35 inches long.