52mm Car and Boat Tachometer Marine Tachometer with LCD Hour Meter 4000 RPM Marine Tachometer 12V/24V Red Backlight Tachometer Features: 1. Racing look enhances the character of your car/vehicle 2. Comes with Installation manual. 3. Red backlight 4. High precision 5. Accessories: Tachometer suitable for cars/trucks/boats/diesel generator engines/gasoline engines Specifications: Material: stainless steel + nickel-plated plastic Working voltage: 12V/24V Connection: Red battery (+9-32VDC) Blue battery (-) Black signal, Orange black light (+9-32VDC) Indicating range: 0-4000RPM, 0-7000RPM Input signal: from speed sensor, engine, alternator, Pulse signal for ignition coil, crankshaft sensor, etc. Adjustable speed ratio: 1-300 Protection level: IP67, can work at 1m underwater position Packaging: 1x tachometer 1x installation instructions or 1 X sensor