**FITS all bikes that have the same clutch master cylinder as on my 19 450sxf which is at least from 17-25. It replaces the master cylinder res. cap. double check your years etc, I just plugged in on here all years... how it works - https://www.keeferinctesting.com/slipshot-holeshot-traction-control-device/ Your clutch will work exactly like normal in all situations except when you activate this device for a start. Basically you adjust its position so you pin the throttle and pop the clutch when the gate drops and it slowly and precisely releases the lever however you tune it so it's repeatable time and time again. Just bought the bike used and the original owner put this one and wouldnt shut up about how nice it was. I dont race anymore or practice starts so figured id pass it on to a young racer. give it a shot!