Extra-Duty On/Off Diesel Power Battery Switch 3 studs heavy-duty diesel power battery switches are built with heavy-duty copper sweep contacts to ensure positive circuit control. Rugged internal components are protected by a tough, impact-resistant polycarbonate housing that is impervious to the elements. They also feature Alternator Field Disconnect (AFD) allowing selection of any position, including 'off', without damage to the alternator or electrical system. Features: * Guest 2304A Extra-Duty On/Off Diesel Power Battery Switch Model: 2304A  * For 6, 12, 24, or 36V systems * Cable lug size: 1/2'