LaserLyte Laser Training Cartridge .233 LT-223: * Fits inside the cartridge chamber * Firing-pin activated switch that indicates bullet impact with a bright red laser dot * Built-in snap cap protects the firing pin * O-rings hold the laser accurately in place allowing for repeated dry fire practice without compromising accuracy * Rim-less cartridge trainer * Rimmed sleeves are made of solid brass and work perfectly in all bolt-action rifles * Uses three 377 batteries * 3-year limited manufacturer warranty