Quickly diagnose trailer wiring issues before hitting the road!Trailer Light Tester Box is a compact, durable solution designed for mechanics, rental locations, and DIY haulers. Just plug into a trailer's 7-way or 4/5-pin connector to instantly check brake lights, turn signals, and running lights. Works with M18 Milwaukee power tool batteries Features: Easy plug-and-test functionality Powered by a 12V - 24V Milwaukee power tool lithium battery Switches include Power, Trailer lights, Left Signal and Right signal Works with standard 7-way and 4-pin trailer plugs External grounding pin LED switch indicators LED Volt Meter to monitor Battery voltage LED Amp Meter to analyze electrical harness and circuit integrity Rugged, weather-resistant casing Perfect for: Rental yards Fleet managers Mechanics RV and trailer owners Safety inspectors **BATTERY NOT INCLUDED**
