F.Y.I. Here are the outside diameters for all of SkiersChoice towers. The Moomba XLV is 2.39"(2 3/8" ). The Supra Launch and Gravity edition towers are 1.89"(1 7/8" ). All other cages are 1.66"(1 5/8" ). This may come in handy when ordering light and speaker mounts. Brian Raymond