Simply loosen the .125" steel set screws and set your height. Collar has a 1.250" center hole and two set screws with one pinch bolt. Collar is .440" thick, with a .125" step that is turned down to 1.390" O.D.
This slip collar also fits the RCD mag drive #2500-0010R or #2500-0010Q. Perfect when trying to adpt. a distributor or mag drive with a slip collar and the collar fitting in the mag drive clamp.