A piece of suspension hardware used on some moving lights, most notably those from Martin. The shape slightly resembles an elongated version of the Greek letter omega: Ω. Two quarter-turn fasteners fit into sockets to attach the bracket to the fixture, and a clamp of one's choosing is bolted to the bracket using the hole in the center.
Martin Professional OMEGA BRACKET 1/4-Turn Bracket (for Various Light Fixtures) | Full Compass
Martin Professional OMEGA BRACKET 1/4-Turn Bracket (for Various Light Fixtures) | Full Compass