Trailer Light Tester, 7-way 4-pin Adapter for Truck, Van, And Boat Trailers.
【Function】Easily test both 4 pin and 7 way Trailer Connector Tester with this versatile 2 in 1 trailer light tester, simplifying trailer circuit checks on most trucks. 1 Trailer Light Tester. It's just take you 1 minute.