Open a 3-3/8 inch dimension and 2-3/4 inch depth hole, insert the gauge and secure it in place. Easy hook-up with 3-wire connection (power, ground, lighting). This is a complete unit that works directly with a GPS sensor; no additional sensor cables required. Mount the sensor at any position, on or under the dashboard. Takes approximately 30 seconds to acquire signal the first time, and less than 3 seconds thereafter. Performance improves with a clear view of the sky. If signal is lost, reconnect all wires and restart the unit. Displays current speed and odometer (non-resettable), without trip meter function. Features: Low power consumption, long service life, high precision, fast location confirmation, and short startup time. Speedometer range: 220 km/h Voltage: 12V/24V Application: Universal fit Color: As shown Material: ABS + metal Size: 75mm x 90mm x 85mm Package Contents: 1 x 220 km/h Speedometer 1 x User Manual (English and Chinese) 1 x Multi-plug socket Note: Lighting and display differences may cause slight color variations between the image and the actual item. Measurement error allowance: +/- 1-3 cm. Only the items listed are included; other accessories are not part of the package.