Here are the installation instructions for the CNSPEED Speedometer:Prepare the Installation Hole: Open a hole with dimensions of 3-3/8 inches in diameter and 2-3/4 inches in depth.Mounting the Gauge: Place the speedometer gauge into the prepared hole and fasten it securely.Electrical Connections: Connect the gauge using three wires: power, ground, and lighting. Ensure proper connections for seamless functionality.Compatibility with Sensor: This unit is a complete package and can work directly with a sensor without requiring additional sensor cables.Sensor Mounting: Mount the sensor at any desired position, either on or under the dashboard, for optimal performance.Signal Acquisition: Initially, it may take up to 30 seconds to acquire a signal. Subsequent signal acquisition times will be less than 3 seconds, particularly under clear sky conditions. If the signal is missing at any point, reconnect all wires and restart the unit.Display Functions: The speedometer displays current speed and odometer readings, which cannot be reset. It does not feature a trip meter function.Key Specifications:Speedometer Range: Up to 220 Km/hVoltage: 12V/24VApplicable Models: UniversalMaterial: ABS and MetalSize: 75mm x 90mm x 85mmPackage Contents:1 x 220Km/h Speedometer1 x Chinese and English Manual1 x Multi-plug SocketPlease note that variations in lighting and display settings may cause slight differences in the color of the item depicted in the picture Compared to the actual product. Additionally, a measurement error of 1-3cm is permissible.