The ProX 4' Crescent Bar with Two Welded Pro Clamps attaches to any standard 2" trussing and provides 4' of length in an arced design. It attaches to your truss via two professionally welded clamps and allows you to mount DJ lighting and other lights in creative ways. The 4' length provides the room for mounting many lights while the arc offers angles that can't be achieved with straight bars or poles.