4-way with downward outlet. The standard version of the PRO-30 is made from a 50 mm aluminum tube and is 2 mm thick, but there is also an option for a 48 mm aluminum tube (3 mm) available for an additional cost. This is the most common system for clubs, stages, theaters, and many other events. The PRO-30 is available in the following configurations: 2 point (Step System), 3 point (Triangle), and 4 point (Square System). The system elements are joined together with conical connections.