For use on 1-4 axle trailers equipped with electric brakes, these complete systems incorporate the highest quality components in trailer breakaway systems and meet or exceed Department of Transportation (DOT) specifications regarding trailer breakaway and holding requirements.•Automatically applies consistent braking power to your trailer brakes if a breakaway occurs between tow vehicle and trailer•Includes weather-resistant, heavy-duty polymer case to protect battery and charger•Quick and easy to install•Includes Polymer Batter Case with A-Frame or Post Mounting Bracket, Rechargeable Sealed 12v 5 Amp-hr Lead Acid Battery and Terminals, and Breakaway Switch For use on 1-4 axle trailers Polymer case to protect battery & charger | Tekonsha Shur-Set III Breakaway System