Notethe Pointer will not on the Zero when you receive ,it is normal, after connect to the car , the gauge will be work well.Range:Boost gauge psi: -30-30in.Hg Boost gauge bar: -1-2Bar Vacuum gauge: -30-0in.Hg Water temp gauge: 40-120 Oil temp gauge: 50-150 Oil press gauge: 0-100Psi Volts meter: 8-16V Tachometer RPM: 0-8000RPMFeature1. White Digital LED Readout. 2. Easy install,comes with installation instructions 3. Electronic Gauge has the Opening Sweep Movement.Fitment:Only Fit for 12Volts gasoline Car (Tachometer only fit 4/6/8 Cylinder)Instruction:1. Easy Installation With Users Manual In English 2. Comes with Mounting and Installation hardware. 3. Professional Installation is Highly Recommended. 4. Add a racing look and feel to your ride,High quality and light weigh.