the G3 have multy speed option .
mode a : max speed 6 km/h start by push
mode b max speed 12 km/h start by push
mode c use 3 speed (low acceleration) the speed are 12 km/h , 20km/h and 28km/h
to set the speed move the mode to c .
now , prees and hold the left brake + throttel push for 5 sec. release the throttel and release the brake . now the speed will change
mode d , change the speed same like change for mude c
mue d is high acceleration.