Features: Used to measure the RPM of automobile engine. Measurement range is 0~8000RPM. High accuracy and easy operation. Works on 1, 2, 3, 4, 5, 6, 7, 8 cylinder gasoline vehicles or 1-2 cylinder motorcycles. Adjustable shift light on face. Note: 1. It's normal the pointer is not zero in the absence of installation. After power-on, the product will check and adjust the pointer by itself. 2. If the product pointer is still not zero after power-on, it can start normally; when the pointer is above zero, it can be restarted to adjust the pointer after power-off. Specifications: Color: Black Material: ABS Background light: Blue light Input Voltage: 12V Package Size: 14 x 14 x 14cm (5.5 x 5.5 x 5.5in) Weight: 367.5g (13oz) Package List: 1 x 3.75" Tachometer Gauge 1 x Installation Instruction 1 x Fitting Kit Note: Not suitable for diesel vehicles. Only for 12V petrol vehicles.