There are three parts to the laser tag guns namely (1) shooting LED, (2) hit indicator LED, and (3) photodiode. This device can be used to test these three components. Here is a picture of a gun connected to the tester.

The most common elements to fail is the shooting LED.

Here are the steps for using the gun tester:

1. Plug the two gun cables into the tester.
2. Pull the trigger.
3. Verify that the shooting LED comes on.
4. Verify that the hit indicator LED (on the top of the gun) comes on
5. Place the gun into the tester. Make sure that the tester LED is aligned with the gun photodiode.
6. Pull the Trigger.
7. Verify that the LED on the side of the gun tester comes on.