This wireless socket tester allows to easily identify incorrect or faulty operation of trailer lighting. It is made of durable ABS polymer and has got four LED indicators. It is used to test working order of the wiring system and bulbs. Thanks to the included adapter (13/7 and 7/13) it can be also applied to test devices with 7-pin standard. The set includes: 7-pin trailer socket tester, 13/7-pin adapter, 7/13-pin adapter.