The fan is all about customization. The Zonex GM Cabinet Series is designed to operate on a single speed (400, 500 or 700), 2 speed fans (400- 700 or 500-700) or 3 speed (400-500-700). Our multi-speed fans can run quietly all day at low CFM and provide hi-speed boost ventilation when you need it, or work with regular line voltage on/off switches.