Hi Hugh the silver coloured lever is the mechanical brake lever sensor which I had on the other bike now just connected to the bike as a sensor only, a little pull cuts the motor just in case I happen to need it for changing gear etc, most of my riding is done on gravel paths and roads so think should be ok without brake sensors, and there’s no requirement here to have them , l too have ridden all sorts of motorcycles over the years on the roads only I have given them up as now to old lol. Just have to make do with E bikes nowadays not a bad thing as they were getting a bit too dangerous.