Our Kwiki line of bright, zinc-plated residential regulators is designed to allow easy installation onto any factory-made residential quality damper blade. The spring in the spring-loaded bearing will never bind or interfere with the blade. Both our KB-1 (Spring- Loaded Bearing) and our KM-1T (Threaded End Bearing) will perforate the metal with ease every time. Our special handle can also be used on both ends simply by flipping it from one end to the other. Both ends are available with steel back-up washers and gaskets to resist leakage.