This retainer is for use wth the clamps that were used in a variety of applications on a wide range of early Margay karts. Clamps were intended for use on 1” or 1 1/8” tube with 1/8” thick neoprene rubber insert.). UPDATE-as of 1/23/24 we currently have only the zinc plated retainers in stock. We do hope to produce the clamps again at some point. Clamps shown below in use for rear bumper mounting: