Our snap caps allow for safe release of firing pin springs. A spring loaded striking area cushions and protects firing pins. An excellent tool for teaching and eliminating flinching. Features: Prevents damage and prolongs main spring life Precision machined to true SAAMI specs Primer material is correct hardness to prevent striker/firing pin over-protrusion Aluminum won't damage the chamber/extractor/ejector Snap caps are a critical training aid for learning how to fix malfunctions quickly and efficiently not only for competition shooters but for anyone who has a gun for self-defense Packages of 5 snap caps are bare minimum for training with multiple magazines for pistols