Load Rite 20,000lb Capacity Disc Brake Actuator w/2-5/16 Coupler [6080.60]20,000lb Capacity Disc Brake Actuator with 2 5 16 Coupler The Model works by the surge or push of the trailer toward the tow vehicle. This automatically synchronizes the trailer brakes with the brakes on the tow vehicle. 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. The built in, sealed, independent dampening shock absorber