HKS MK3-A Revolver Speedloader for Colt MK3 & MK5/King Cobra/Peacekeeper/Ruger Security 6 Fits medium size speedloader case; Made in USA Loads cartridges into revolver instantly No cartridge jiggle Popular twist knob Caliber .38/357; Fits Colt MK3 & MK5/King Cobra/Peacekeeper/Ruger Security 6