Shimano SW-EM800-L Switch Unit for Assist Left HandShimano SW EM800 L Switch Unit for Assist Left Hand To control the power mode on the STEPS drive unit you can easily toggle between, Off, Eco, Trail and Boost support modes plus Walk Assist mode. Should you get to a part of the trail where riding is not possible, you can active walk mode but pressing and holding the shifter down for assist up to 6kph. Easy to reach without having to move your hand from the grip with adjustable paddles Customisable