The Pro-Shot 20 Gauge Snap Caps feature beautiful brass heads with spring-loaded firing pins designed to safely release tension when dry firing your shotgun.Pro-Shot 20 Gauge Snap Caps - 2 per packageHigh-quality brass construction for durabilitySpring-loaded firing pins for realistic dry fire practiceWool mops with natural lanolin for chamber rust protectionCompatible with Zero Friction oil for enhanced protectionEssential for safe dry fire practice and long-term shotgun maintenance these snap caps protect your firing pin while keeping your chamber free from rust and corrosion.