The small rev. counter is designed for the race, so we try to make it very small and work on the inner battery. There are tachometer, thermometer, the engine running hour, MAX record, and the RPM & temperature alarm functions including in the rev. counter, so you could get almost all the basic function you need for the race with it. If you want to use the meter on your bike every day, you could also connect the Backlight power to your battery and enable the Backlight function.