Awesome flybys. Just a friendly word of advice... never race more than two bikes at a time. You can run into to the back of each other or crash into each other when there’s more than two.
It's a quickshifter, allows clutchless shifting, essentially letting the gear slip in when shifting. It cuts the spark plugs very briefly to allow it. Same thing as quickly letting off the throttle and shifting up, just this is more consistent and comes on most higher end bikes
