This innovative hydraulic trailer brake actuator has a unique all-aluminum master cylinder that incorporates the shock absorber into the master cylinder assembly. This warns the vehicle operator when the brake fluid is low. The oversized master cylinder provides the higher pressures required to run trailer disc brakes and the added brake fluid volume to run both tandem and tri-axle configurations. Higher pressures mean quicker stops when using traditional drum brakes. Preloaded dampener unit means you no longer have to "pump" the dampener before bleeding the brakes. Drop-N-Go auto latch features a 2" coupler that when closed will automatically latch onto the hitch ball. Fits trailer frames up to 3"W x 5"H and accommodates 2" hitch balls.