Amazon.com : Sling Rings 3-inch Diameter by Cutie Carry. Infant Approved, mom Loved. Aluminum, lab Tested for Strength and Safety. Works with Your own Material or Convert wrap to Sling. (Dark Grey) :
Fidella ® Sling Ring for Baby Wraps
Amazon.com: Nalakai Ring Sling Baby Carrier. Eco-Friendly, Soft Bamboo and Linen Baby Sling, Baby Wrap. Comfort, Style, and Giving Back - Carry Your Little One with Love : Sports & Outdoors