This is one cool item! Our new KOSO Mini Recall Tachometer is the perfect tach for the rider or racer that wants to see peak RPM of their engine. Just wrap the single wire around the plug wire and you're ready to go! The tach can be programmed for any spark pulse. Tach size is 1 1/4 X 2 1/4. Things like clutch engagement, peak RPM on the track, engine over rev, and many other things can be checked with this recall tach. Ours comes with all mounting hardware.