A ring sling is a long piece of fabric sewn onto a pair of rings. The "tail," or end of the fabric, is then threaded through the rings. The wearer places the sling over their head with the rings on one shoulder, and baby goes into the pouch formed by the fabric. The wearer pulls on the tail to tighten or loosen the individual "rails," or top and bottom edges of the fabric. Ring slings have excellent adjustability. I recommend them for parents of all sizes, particularly for couples of different heights and builds.
Baby ring slings are best used for front and hip carries, and are excellent for discreet nursing. The tail also provides a useful cover for privacy or weather protection. Ring slings can generally be shared by wearers of different sizes, although the tail will be longer on a smaller person and shorter on a larger person.
Ring slings have relatively low learning curves, and take very little time to set up and start babywearing. When sized and adjusted properly, with the fabric well-spread over the wearer's back and the baby worn high and close to the wearer's body, ring slings and pouches are very comfortable baby carriers. They are particularly useful for the newborn and baby stages, and for the toddler "up down" phase - just leave the carrier on and pop the baby in and out! For those with back and shoulder issues, or for hours-long babywearing comfort, though, many parents find a two-shouldered carrier more to their liking.