Mounts on jackpost or A-frame with one bolt installation. Weather/Corrosion resistant. Meets or exceeds D.O.T. specifications. 12 Volt battery fits securely in battery case with optional battery charger. Compatible with all automotive electrical systems. Automatic shutoff can’t overcharge battery. Intended for use on single, tandum, and tri-axle trailers with electric brakes. Breakaway Kit includes: Battery case with mounting bracket, 12 volt sealed rechargeable battery and nylon breakaway switch. Note: Battery charger optional