Google ruins everything. Winner!!Yes, Cutts Compensator. Chokes screw into end ahead of compensator(recoil reducer). First made in the 30's by Lyman. I always had the spreader(cylinder bore), short one in picture. I recently saw the longer one (modified) for sale in ebay and picked it up pretty cheap.(25.00).Sure looks like one of the old poly chokes. I just looked it up, it?s a Lyman Cutts Compensator Choke.