We chose this bike computer because it has GPS. A conventional wireless speedometer cannot be attached to the heater seat on a tandem bike because the distance from the heater to the rear wheel is too great. So we decided to use GPS. Unfortunately the GPS on this bike computer is faulty. When it tries to initialize it, it often hangs. Or if you stop for too long during a ride, it freezes. The cure is to turn it off and then turn it back on. But that erases the kilometers per trip. Another limitation of the device is the short battery life. In GPS mode, the device only works for a few hours. If left overnight, it's dead by morning.