New 1Pc Nylon 7-Pin Truck Trailer Plug Socket Tester Wiring Circuit Light Test Tool Easy to Carry and Use Specifications: This tester has one side to connect the 7-pins plug of a trailer and another side to connect the 7-pins socket of a car. This tester indicates quickly if a failure concerns the wiring of the car or the wiring of the trailer. Can effectively test what the problem is for 7 pins plug and socket connection. Cross slotted copper needles, cooperate with the female pin. Safe and dependable performance, reasonable design. Easy to carry and use. Item Name: 7-Pin Trailer Tester Material: Nylon + Copper Battery Type: AAAA Battery(Not Included) Length: 20cm/7.87" (Approx.) Width: 5cm/1.97" (Approx.) Height: 4cm/1.57" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x 7-Pin Trailer Tester