Features: * 100 percent solid-state electronic designed for use with 2 to 8-brake systems * Overload and digital output indicator * Thumb wheel adjustment control rate from soft to aggressive * No moving parts or pendulums; no leveling required * Compatible with anti-lock braking systems * Covered by additional circuit protection will not be damaged if black and white wires are reversed What"s In The Box: * Reese Towpower 74643 Digital Brakeman Brake Control Trolley with Digital Display