Global Truss Circular Truss Topper [DT-DYNO WHEEL] Round truss topper for F34 series square truss. This is a perfect addition for anyone that uses vertical trussing and wants to add a cleaner, more presentable look to their lighting. The DT-Dyno Wheel can be used to mount multiple moving heads, wash lights or even black lights or scanners. Really any type of lighting fixture you can imagine can be used with this great new vertical trussing accessory. Works with 12x12 size box truss as well as single tube.