Features: 1.Trailer Tester: This tester has one side to connect the 13 pins plug of a trailer and another side to connect the socket of a car, makes it convenient to use. 2.Main Function: This trailer plug tester can help you to quickly check the circuit failure of both vehicles and the electrical system on trailers, and resistance test. 3.Durable Construction: Made of high strength ABS plastic and copper, which is impact resistant, wear proof, anti aging, and has long service life. 4.High performance: Using brass as conductor, with good electrical conductivity, ensuring more stable function and high practicality. 5.Fine Workmanship: Requires 9V, PP3 battery power, (not included), can test trailer, caravan lights without attaching to a vehicle, very simple to use. Specification: Item Type: Trailer Tester Material: ABS, copper Specification: 13pin Voltage:12v Material: ABS, Copper Color: Black Function: Resistance test, detection of faults on the line Power Supply Mode: 9V PP3 Battery Required (Not included) Application: Suitable for RV, trailer