Main Material --- Quick Check of ABS and Copper --- This trailer connector has one side to connect the 7-pin plug to a trailer and another side to connect the 7-pin plug to a car. This tester quickly indicates if there is a fault in the car's or trailer's wiring and effectively tests the problem with the 7-pin plug and socket connection. European Universal Standard --- Meets European CE and ROHS certifications, ensuring maximum strength and durability for long-term use. Such a practical trailer testing tool you need. Reliable Quality --- 7-pin trailer tester with safe and reliable performance, reasonable design. Skillful appearance, practical use. The trailer tester connector is suitable for caravans, RVs, camper vans, vehicles, trucks, trailers, etc. The test requires a 9V battery (not included) High Performance --- The trailer connector tester is made of high-quality ABS and copper, the frosted surface is durable and reliable, ensuring resistance and maximum durability for long-term use. One side connects to the 7-pin plug and the other to a 7-pin socket, can also be used for 13-pin with the adapter. (7-pin Trailer Tester + 2 x 7 13 Converters)