Upgrade your trailer testing experience with the NEWSUN 7-Way Blade & 4-Pin Trailer Light Circuit Tester! This versatile testing tool combines a 4-way circuit tester and a 7-way trailer light tester in one convenient device. With our 2-in-1 design, you can effortlessly test both 4-pin and 7-way connectors on most trucks. No need for multiple testers or adapters! Not only does our trailer light tester act as a 7-pin to 4-pin trailer plug adapter, but it also offers a comprehensive 6 light functions testing. Quickly confirm the functionality of taillights, brake lights, reverse lights, turn signals, electric trailer brakes, and 12V auxiliary power on your vehicle. Equipped with bright LED indicators for each electrical function, our tester allows for easy and accurate identification of any wiring issues. No more guesswork or frustration! Constructed from durable ABS material, our 7-way blade RV trailer tester is built to last. Experience reliable performance and peace of mind knowing that your testing solution can withstand the demands of the road. Upgrade your trailer testing game today with the NEWSUN7-Way Blade & 4-Pin Trailer Light Circuit Tester. Ensure your trailer lights are working flawlessly for a safe and worry-free towing experience!