These A Zoom Metal Snap Caps for 350 P are hard anodized to ensure smooth cycling and a long lifetime. They are CNC precision machined from solid aluminum to the precise cartridge dimensions, then hard anodized for extra-smooth functioning and long life. This makes them much more reliable and durable than injection molded snap caps. These A-Zoom 350 Legend Snap Caps are perfect for shooting training both beginners and professionals. They are a safer alternative to using live rounds, and can be loaded in a magazine for function testing or to safely stow without damaging the firing pin. You can also use them for annual function testing to make sure all is working properly. They are a much safer and reliable method to use than using newspaper, a magazine full of air or even a DV camera - not to mention a Snap Cap!