• 2 in 1 Design: This trailer light tester combines both 4 way circuit tester and 7 way trailer light tester, allows you to test both the 4 pin and the 7 blade connectors; Easy and quick to test trailer circuits on most trucks;
• Acts as a 7 Pin to 4 Pin Trailer Plug Adapter: 7 way rv trailer tester can be also used as a 7 way to 4 way trailer adapter, converts the vehicle-side 7 pin output to a 4 pin flat adapter to connect the 4 way trailer light plug
• 6 Light Functions: Versatile trailer wiring tester can be used to test 6 separate trailer light functions, quickly confirm the functionality of taillights, brake lights, reverse lights, turn signals, electric trailer brakes and 12V auxiliary power on your vehicle
• Bright LED Indicators: Plug in 4 way and 7 way trailer light tester equips a LED light for each electrical function; Plugging the light tester and check, you can easily read the green LEDs and find out which wiring has a problem
• Durable Construction: For long-lasting use, this 7 blade RV trailer tester is made from durable ABS plastic, which will never rust or corrode, Tin-Plated copper terminals makes great conductivity
• Simple to Use: No batteries or wiring needed! 7 Blade & 4 Pin Tester is easy to use, ergonomic design is convenient for plugging in or unplugging; Widely used to test trailer light circuits on most Trucks, Boats, Trailers Campers, Caravans, Food Vans and other Towed Vehicles
• Note 1: The trailer tester will upside down when testing for 2017 Newer Ford/GMC/Chevy model; Note 2: 7 pin trailer plug tester is unable to test LED lighting system; Note 3: Doesn't work with vehicle has a lamp-out sensor, such as BMW, VW, Audi, Mercedes-Benz, Porsche etc.