"Our GPS Speedometer category contains a variety of speedometers to fit almost all Boat, RV and Automotive applications. Put a GPS speedometer on almost anything that has 12 Volts. Ideal for all speed applications and particularly useful for craft where traditional speed sensors like pitot tubes and paddlewheels do not perform well. An additional benefit is there are no elements that can corrode or break. Different Brand models have built in or separate antenna. If you can't find what you are looking for call us, we'll be glad to help!