Hopkins 20400 Engager FT Break Away System with LED Battery Monitor Activates trailer brakes upon separation from the tow vehicle Built-in LED battery meter verifies battery charge and built-in battery charger charges battery while connected with the tow vehicle Complete system includes box, battery, charger, 7 inch switch, and hardware 1-2 axle capacity, uses a 5-amp hour battery Break away system exceeds D.O.T. regulation 393.43 (d)