- The Rapit® is an inexpensive, rattle-free regulator for quick installation on balance or splitter dampers. It is formed from rust-resistant, heavy gauge, galvanized steel and installs in seconds. The Rapit® will penetrate and secure to round or rectangular damper blades up to 24 ga steel. It has a fully retractable bearing of zinc alloy, threaded to accept a 5/16-18 wing nut and a handle that indicates the damper position.