Specifications: Material: Plastic and Brass Voltage: 12V DC Contents: 1 x Tester 2 x Adapters (one is 7-pin to 13-pin, the other is 13-pin to 7-pin) Tips: The body plugs directly into 7-pin N-type plugs or sockets and performs a continuity test on all lighting circuits. Power source Battery powered 7-way color trailer tester About this item Quick Check - The 7 Pin Electrical Diagnostic Tool Tester is designed to quickly report faulty wiring on towing vehicles and trailers. Easy to Assemble - This 12v brake light tester is easy to use. One side connect to 7 pin plug and the other side connect to 7 pin socket, also can be applied to 13 pin with adapter. Premium Quality - These electrical wiring testers are selected with superior plastic and cross grooved copper, which naturally matches the female pin. Heavy Duty - The 7 way trailer plug tester set is normal European standard. It can be widely used in car, caravan, motorhome or other commercial vehicle freely. Kind reminder - The trailer circuit tester requires a 9V battery (not included).