A Moon clip is circular piece of spring steel or stainless steel designed to hold a full cylinder of ammunition for a revolver together as a unit. Therefore, instead of loading one round at a time or using a speedloader, with a Moonclip, a full cylinder of ammunition can be loaded and the fired cases are all extracted together as a unit. Thus expediting the revolver loading and unloading process. Unlike a speedloader, a Moonclip remains in the revolver during firing. Loading and unloading tools for the Moonclips are recommended to assist the shooter with these administrative functions. A moon clip loader greatly speeds up the process of loading your moon clips. TK Custom™ carries a full line of competition products for Smith & Wesson as well as other popular manufacturers. Visit our Products page to purchase moon clips and accessories for your S&W 340, S&W 642, S&W 66, S&W 686 and more!