Any clothing or accessories that have an O-shaped ring through which parts of a garment can pass and then connect together. Any types of clothes that aren't implicated here can just use this tag as a placeholder, rather than creating new tags for every type of o-ring clothing.
For the time being, "o-ring" also covers all other loop shapes, such as ovals, rectangles or any thing else containing a hole. For hearts, use heart o-ring.
The following tags implicate this tag: o-ring_belt, o-ring_bikini, o-ring_bottom, o-ring_choker, o-ring_harness, o-ring_legwear, o-ring_swimsuit, o-ring_thigh_strap, and o-ring_top (learn more).