UFP DX7.5L A75 Drop-N-Go Surge Actuator - Single AxleThis UFP by Dexter Drop-N-Go disc brake surge actuator works by the "surge" or "push" of the trailer toward the tow vehicle. This automatically synchronizes the trailer brakes with the tow vehicle axle brakes. When the trailer pushes against the tow vehicle, the actuator telescopes together and applies the force to the master cylinder, supplying hydraulic pressure to the brakes.Product Features: Capacity: 7,500 lbs; 1 Axle Application; UFP Model 47723; Fits 2" Hitch Balls; Greasable Rollers; Aluminum Master Cylinder; Zinc Plated; Bolt-On Mounting; Integrated Reverse Solenoid;