Hopper fed, loose ammo loader For 9mm Luger FMJ Ball/Round Nose rounds Compatible with GLOCK, SIG, Smith & Wesson, Springfield Armory, Ruger & CZ 50-round capacity hopper Reduces magazine loading time by more than 50% Mounts to any Weaver or Picatinny rail Built-in safeties prevent damage to rounds and stops loading when magazine is full Self-sorting hopper orients ammunition in either direction Eliminates hand fatigue caused from loading Requires much less physical effort and strength Lightweight, durable polymer construction.