Breakaway Kits are intended for use on single, tandem and tri-axle trailers equipped with electric brakes. Mounts on jackpost or A-frame. Quick, easy one bolt installation, no need for cutting or drillingWeather/Corrosion Resistant. Rust-proof heavy duty polyethylene plastic case protects battery and charger from elements and corrosionMeets or exceeds D.O.T. specifications regarding Breakaway/holding requirements. Most states require breakaway switch with separate power supply when towing a trailer!