The MILWAUKEE? SHOCKWAVE Impact Duty? 3/4″ Drive 1-9/16 to 2 17mm to 60mm Retaining Rings are optimized for 1-9/16″ to 2″ and 17mm to 60mm size impact sockets, when additional socket retention is needed for 3/4″ drive impact wrenches. The convenient one-piece design and flexible rubber material make the installation of the retaining ring hassle-free. It’s necessary to use the proper retaining ring for each socket size.