"M" Series Speedloader loads cartridges into revolver instantly. The principle is simple, strong metal points hold cartridges securely in the loader until you release them into the revolver with a turn of the speed loader knob. Fits S&W 29, 629/Dan Wesson/Ruger Redhawk/Super Redhawk/Colt Anaconda/Taurus .44, 444 Raging Bull