Carlson's Choke Tubes Aluminum Shotgun Snap Caps 28 Gauge 2 Pieces Red 42. Spring-loaded primer plunger prevents firing pin damage during dry-firing exercises. NOTE: leaving guns cocked during storage is hard on springss and is dangerous. These will help keep your firearm in good condition. Set of 2. Specifications for Carlson's Choke Tubes Aluminum Shotgun Snap Caps: Manufacturer: Carlson's Choke Tubes Fabric/Material: Aluminum Quantity: 2 Gun Type: Shotgun Color: Red Features of Carlson's Choke Tubes Aluminum Shotgun Snap Caps: 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. Package Contents: Carlson's Choke Tubes Aluminum Shotgun Snap Caps Carlson's Choke Tubes 42: Aluminum Shotgun Snap Caps 28 Gauge 2 Pieces Red