Treningspatron m/Laser, .223 REMLaser training cartridge for Rem . 223. The red lasers flashes briefly when firing pin strikes the rear rubber cap on the cartridge. Perfect for dry fire training! The rear rubber cap is an item that eventually wears out. The number of impacts it can withstand varies from weapon to weapon, but we have tested these for up to 300 impacts without issues. While competitor products will charge you extra for spare rear caps, we include TWO extra rear caps