This laser trainer fits all of the most popular pistol calibers, mounts inside the barrel and has the sound activated switch showing bullet impact with a laser dot. Every time your hammer or striker fires the small laser dot will flash for 100 milli-seconds simulating bullet impact. This is the next evolution to the LaserLyte line of laser trainers. This model installs from the muzzle of the barrel and fits tight with the use of LaserLyte’s patented arbor and taper system. The system will fit the weapons chambered in 9mm, 40 S&W, 45 ACP that have a minimum of a 2 inch barrel. The LT-Pro will also fit calibers 38 special, .380 Auto, 357 Sig, 10 mm and 45 LC.