The ERGO Baby Carrier s ergonomic design supports a correct sitting position for the baby s hip, pelvis and spine growth. The ERGO also balances the baby s weight to parents hips and shoulders, and alleviates physical stress for the parent. Special Features. Recommended use up to 40 lbs. Can be worn on front, back or hip and easily shifted from one to the other. Waist circumference extends from 25 up to 43 and with the additional Waist Extender 8 can be added. Attached Sleeping Hood supports sleeping baby s head and expands with the growth of your child. Padded waist belt supports the lumbar area plus 1 thick padding in the shoulder straps. Allows for freedom of movement because the parent and baby are like one. Convenient pocket on back of carrier with side zipper for easy access. 100% cotton canvas outside and 100% cotton poplin lining and hood.