Stop your car's mileage for dyno testing purposes with this adapter. Original german-manufactured wiring ensures years of reliable service and does not interfere with any of vehicle's primary functions (e.g. speed indication). Make sure to mention your Mercedes model and year during the checkout. Installation is quick, however we recommend it to be carried out by a professional. Necessary instructions will be provided. Not Legal for public road use. Check Your local laws and regulations if you're allowed to use this device in your country.