A-zoom strikercaps are made without a rim and are equipped with a centering o-ring which grips the chamber walls and keeps the snap cap in place in the chamber.Once it is chambered, simply rack the slide to cock the pistol.Strikercaps will absorb the firing pin hit just like standard a-zooms, however will stay in place for quicker, easier dry fire practice.Type: Snap CapsCaliber Or Gauge: 9mm LugerRounds Per Box: 2Material: Aluminum