Open a 3-3/8 inch dimension and 2-3/4 inch depth hole, insert gauge and secure. Easy installation with 3-wire connection (power, ground, lighting). Complete unit that works directly with GPS sensor; no additional sensor cables required. Sensor can be mounted in any position, on or under the dashboard. Acquires signal in approximately 30 seconds on first use, and within 3 seconds on subsequent startups. Faster signal acquisition under clear sky view. If signal is lost, disconnect and reconnect all wires and restart. Displays current speed and odometer (non-resettable); no trip meter function. CNSPEED Speedometer features low power consumption, extended lifespan, high precision, quick location confirmation, and short startup time. Speedometer range: 220 km/h Voltage: 12V/24V Application: Universal Color: As shown Material: ABS + metal Size: 75mm x 90mm x 85mm Package Contents: 1 x 220 km/h Speedometer 1 x Chinese and English Manual 1 x Multi-plug Socket Note: Light shooting and different displays may cause the color of the item in the picture to vary slightly from the actual product. Measurement may vary by +/- 1-3 cm.