Check the listing for details. Hunter Threaded Rim Stud Retainer Kit 20-1688-1. Condition: New. Listed at 28.95 USD. Automotive Equipment Solutions Rim Stud Retainer Kit for Hunter Style Alignment Clamp Threaded Rim Studs 8pc. These are the steel stud retainers pressed into the ends of the alignment sensor wheel clamp assemblies that the threaded rim studs screw into. (as shown in picture) Standard size and thread type used on Hunter alignment systems equipped w/ up to 20-inch self-centering adaptors. (May fit other models as well.) Outside diameter of end that presses into the wheel clamp is 1/2 inch with 3/8” x 16 female thread. Outside diameter of the back side w/ O-ring approx. 9/16” and is used to store the sleeves that slide over the threaded rim stud when not in use. What else can we help you find? Visit our eBay store! http://stores.ebay.com/autoshoptoolandsupply Disclaimer- The parts we offer are an O.E. alternative; they are not produced by O.E. Manufacturers such as Accuturn, Bosch, All Tool, Ammco, Coats, FMC, John Bean, Hennessy, Hunter, Kwikway, Hofmann, Snap-On, Van Norman, or similar manufacturers respectively.