Safe for babies from 7-45 lbs. Wear baby on the front facing inward or back. Padded waist belt and shoulder straps for ultimate comfort. One-on-one baby wearing education and support are available. Acknowledged as "Hip-Healthy" by the International Hip Dysplasia Institute. Size XL -4XL but runs a bit small in my opinion. Got this size so my husband could wear our baby as well.