The removable C-clip (located between the compression collar and the frame) is used to secure bayonet style handles. When using a handle with Acme threads, remove the C-clip. This allows the handle to slip further into the frame for a more secure connection.
To Insert the Handle
Unscrew the compression collar (counter clockwise) and slide the collar off of the frame and place onto the handle (with the collar threads facing the bottom of the handle). Bend open the pliable plastic teeth on the frame and insert the bottom of the handle. Slide the compression collar over the threads and tighten (clockwise) until a secure connection is made.