Quick Check - This trailer tester is designed to test 7 pin plugs and sockets on a car and trailer. This tester quickly indicates whether a fault is in the car wiring or the trailer wiring, which can effectively test the problem of the 7-pin plug and socket connection. European Universal Standard - Pass Europe CE, ROHS Certification, universal 7 pin trailer tester For European vehicles, the 7 pin tester can effectively test the problem of lighting connections. Reliable quality - The tester of 7 pin trailers with safe and reliable performance, reasonable design. Skillful appearance, convenient use. Easy to store Can be used with trailers, RV, caravans, bike racks, Testing requires a 9V battery (not included) Easy to Assemble - Made of high quality ABS and copper, its frosted surface , durable and reliable, ensure maximum strength and durability for long lasting use, One side connect to 7 pin plug and other side to 7 pin socket, also can be applied to 13 pin with adapter. /p>