A popular chain used for chokers that has a convex shape (bows outward) and has rectangular links that show parallel lines all along the chain. Omega is an attractive chain used for chokers with slides, but is not very flexible.

Unlike most chains which are a series of linked rings, an Omega chain is made up of rectangular smooth rounded metal plates set side by side and crimped along the ends onto a strip of metal mesh. The end result is a fairly stiff, yet flexible, circle which needs to be worn high around the neck since it is not nearly as attractive when viewed from the edges.