Reverse battery protection for both vehicle and breakaway systems. Designed to work with electric over hydraulic trailer brakes. Multiple mounting options - including 360 degree vertical rotation. No level adjustment necessary - it adjusts itself to varying terrain as you drive. Great for backing into tough spots! Works proportionally in reverse - with the ability to disable when not needed. Produces stops that are in proportion to vehicle's deceleration rate. "Boost" feature gives users the ability to apply more initial trailer braking power. 6"L x 8.5"W x 12.5"H. 1.4 lbs.