TRUST OUR 17 YEARS PROFESSIONAL POWER SPARKMOTO Brand 12V 13Pin Trailer Light Tester Conforms to ISO 11446 Standard. Products Specifications: Voltage Rating: 12V Road Traffic Approval : CE, RoHS Material: Pure Copper Brass Pins and Durable Plastic High Strength Nylon,Better Rust Protection and Prevent corrosion Fast checking if your vehicles’ lights functions are working good or not before you hit the road. Making your driving more safer on the way! Suitable For Cars,Trailers,Caravans,RV,Tow Bar, Bike Carriers,Lorry,Camper Vans,Motorhome. How to use? 1.Open the battery cover on the back and put a 9V battery(not included) inside. 2.Connecting the tester with the plug from your towing vehicles or socket from your car. 3.Press the yellow button on the side of the tester. 4.If the wiring are good, all the LED will light up. 5.If one LED doesn't light up, because the corresponding wire is defective.The function of each LED are according to ISO 11446 on the tester body or refer to the wiring diagram on our web page Attention: Pin 2 can either be used for a warning fog or a permanent 12V connection. Packing List : 1x 13 pin Trailer Light Tester 1x Wiring Diagram Instruction