This is a great addition to the 2016 IZIP E3 Protour, Dash, Sumo, Vibe+ and Peak models. These 2016 eBikes have moved to pedal assist only (no throttle). The boost button brings back most of the functionality of the throttle. If your eBike is a Class 1 eBike it will change it to Class 2 but can be removed fairly easily to return the bike to a class 1 eBike. The button has 2 positions. Position #1 boosts the bike to 6 mph without pedaling. Position #2 boosts to 20 mph without pedaling and overrides the selected power level if pedaling to give full power.