Feature: 1. 3 in 1 Multifunction: The GPS speedometer combines speed tracking, voltmeter, and fuel gauge in a single device for precise, multifunctional monitoring on boats, RVs, and trucks. 2. Installation Size: Cut a 110 mm (4-3/8in) diameter panel hole. You will need a minimum clearance of 55mm (2 3/16in) behind the panel to fit the gauge. Put the gauge in the hole and screw down. 3. Easy to Read: Featuring a red backlight, this GPS speedometer ensures easy readability in all conditions, making it a practical choice for day and night use. 4. Installation Note: For the GPS antenna, you should securely fasten it in the flat position, black side upwards, preferably outside (or inside front windscreen) so that it has a clear view of the sky to pick up satellite signal. Connect the antenna cable to socket in the back of the gauge. And do not cut cable. 5. Enduring Construction: Made with premium metal and an HD mirror, this marine speed gauge ensures long lasting performance and easy maintenance in challenging marine environments. Specification: Item Type: 3 in 1 GPS Speedometer Voltage: DC 9-32V Speedometer: 0-200KM/H Voltage Meter: 8-16V Fuel Gauge: E 1/4 1/2 3/4 F Backlight: Red Fitment: Motorhomes, Yachts, Trucks. Package List: 1 x Speedometer 1 x User Manual 1 x GPS Wiring Harness