Ring slings comprise of fabric that is threaded through two hoops. The sling is positioned over one shoulder and fastened by adjusting the tension of the fabric in the rings. The ring system allows for easy size adjustment and rapid fitting and removal. The material that hangs from the rings can be used as cover for privacy when breast feeding. Because of the uneven weight distribution, parents tend to alternate shoulders, or use versions that have padded slings. These types of carriers are only suitable for smaller babies and can become uncomfortable when a child gets bigger.
Wrap slings are the most difficult kind of sling to fit, but are better in terms of custom fitting. The weight distribution is superior, since the load is spread across both shoulders and around the waist. The wrap sling is simply stretchy woollen or woven fabric that is systematically wrapped around the wearer's upper body to create a snug carrying pouch for a baby. Woollen slings are better for heavier babies. The wrap sling is versatile in other ways too: it can be folded up and used as a changing mat, or as a blanket for a baby.
Bag-style slings work very much like large handbags. They have adjustable straps and the baby is carried in a shaped pouch. There have been product recalls of some bag-style slings and they are not regarded as the safest means of baby transport.