This optional RAM locking knob replaces the original thumb screw in RAM extension arms. In the locked position, turning the locking knob will neither tighten not loosen the extension arm screw, preventing unauthorized removal of the RAM arm or cradle from your motorcycle. It keeps honest people honest - it's not crowbar and buzz-saw safe (of course, neither is your motorcycle). Once you set your mount in the location you need, lock it and hide the key.