This split ring retainer is used with the longer Camloc 4002 Series Heavy Duty Studs (-16 and longer) to keep the stud from pulling out of the grommet when unfastened. Shorter studs (-14 and shorter) do not need this retainer. Sold individually.
Installlation is similar to adding a key to your keyring. To install, slip the Retainer over the end of the stud shank so that it rests on the stud cross pin. Grasp one open end of the ring with a pair of needle-nose pliers and pull it down below the cross pin. Now turn the ring around the stud shank until the other open end falls under the cross pin. (Click "View Catalog Page" below for an illustration.)