The Speedhut GPS Speedometer is your ultimate choice for unparalleled accuracy in displaying your vehicle's speed without the hassle of traditional speed sensors. Installation is a breeze, requiring only 12V power and a waterproof GPS antenna that conveniently mounts anywhere in your vehicle. Forget the hassle of entering tire sizes or gear ratios – no calibration is needed, making it an effortless setup. Operating worldwide with free GPS technology and no subscription, it's a one-way system that solely receives data without transmitting. With its durable construction and user-friendly LCD screen, the GPS Speedometer stands as the essential tool for the performance-driven enthusiast. For easier install also purchase these adapters: https://www.ebay.com/itm/375239350365