I understand the importance of having reliable equipment when it comes to your trailer needs. That’s why I’ve set up the Milwaukee 18-volt drill battery with an 18/20-volt converter to provide a steady 12-volt output. This thoughtful design includes an inline fuse and is connected to six independent switches, along with a 7-pin trailer plug adapter that can also test 4-pin and 5-pin trailers.

When you activate the switches, the turn signals will flash, giving you peace of mind that you're easily visible on the road.

This tester is designed to help you check all the essential features on your 4/5 or 7-way RV or trailer:

- Left turn/brake light

- Right turn/brake light

- Running lights

- Reverse lights

- Trailer brakes

- 12-volt accessory

(Note: Please keep in mind that the battery is not included.)

I want you to feel confident in your setup, so I’ve personally tested the tester box on my own 4/5 flat trailer and 7-way trailer to ensure everything is functioning smoothly.

If you have any questions or need assistance, please don’t hesitate to reach out. I’m here to help!