I'm betting it's the same damn gadget I have in my truck for trailer brakes. You can control it's sensitivity. Betting it has nothing to do with brakes or shifting gears. It's G-force, probably one axis. The harder the truck slows down the more brake voltage is applied. If you jump off your bike and hit a tree, the light will come on. Probably works when in reverse decel as well, which would come in really handy for motorcycling. You could add a strip of LED's that intensify with g-force.