Hello! Thank you for viewing. About the product This is a tester that allows you to easily check the electrical connections of a trailer. It supports 12V voltage and can check the wiring of trailers and towing vehicles with 13-pin connectors. It complies with ISO 11446 standards and can check the trailer's electrical system, including brake lights, turn signals, tail lights, reverse lights, and fog lights. Product Condition ★ Condition Unused (I am selling it because I haven't had the opportunity to use it after purchase) ★ Operation Check Not checked (For those who understand this) ★ Appearance Although unused, there are some minor scratches Key Points! You can easily check the trailer's electrical system with the push of a button, making maintenance very easy! The LED indicators show the wiring status immediately, which helps prevent problems. This is an item that those who frequently use trailers should have. Included Items Main unit only (everything in the photos) Please research the usage and compatible vehicles yourself. Thank you for reading to the end! If you have any questions, feel free to comment!