This thing is amazing - Laser Ammo SPIDER Kit

This is probably the best option I've seen to add a laser function to an airsoft gun. It is absolutely wonderful with the laser ammo targets in toe. I did have problems out the gate but I figured it out. You need to use just a small, small amount of blue loctite on the cartrige that holds the battery or it will come loose in 3 shots. You can't tell when you battery is starting to die until you shoot right at a target and it doesn't register. I also can use this to dry fire on a regular pistol and it works. This deserves more credit than it gets with previous reviews. Sure, you could use pellets, but they make a terrible mess, this solution is just great. The only downside I see is you need to have a holster that will fit a flashlight to practice drawing and engaging.