The bottom drive design saves precious space. High Boyz™ Side Wheels only take up 6 feet of tunnel length, while using a 72-inch tall brush. Hydraulic drive is standard, or you can upgrade to electric drive with a 1hp wash down rated stainless steel electric drive motor and a rigidly mounted aluminum gearbox. A shock and spring are used to hold tension on the side of vehicles, or air-operated controls and retracts can be chosen as an upgrade option. Its simple design delivers excellent wash coverage on the sides of vehicles from the wheels all the way up to the top of side windows of trucks and SUV’s at line speeds of 150 cars per hour or more.