O-ring
From LatexWiki - the free latex fetish encyclopedia
An O-ring is a (usually) metal ring shaped like a letter 'O' and fixed to the end of a flat strap or loop.
O-rings are used in the construction of many pieces of bondage apparatus. They provide an attachment point on clothing or other equipment, and are integral to ring gags.
O-rings are also built into some trousers, to hold the keys and assorted playthings.
