Jager Ultra-Light Glock strikers fit all Glock 9mm, .357, and .40 cal guns. Extremely lightweight at .2 ounces, precision CNC machined from hardened steel to exacting tolerances. Each striker is individually tuned and polished for the most durable, smoothest, lightest trigger pull possible on your Glock firearm. These strikers have been designed with safety and reliability in mind, and will not cause problems such as breakage or doubling sometimes found in other aftermarket strikers. Wolff 4 pound reduced power striker spring is included.