Kit comes with everything needed to replace or upgrade the hydraulic brake system on your trailer from drum brakes to vented rotor disc brakes. Includes model 660 disc brake actuator, brake lines for a single axle trailer and two 10″ stainless steel rotor disc brake assemblies with integrated hubs. For use on 1-3/8″ x 1-1/16″ tapered spindles. 5 stud with 5 on 4.5 bolt pattern. The stainless steel rotor and GalvX finish on the integrated hub provide corrosion protection. Aluminum Caliper and 2 piece piston dissipate heat faster. Actuator feature Drop N Go Auto Latch Coupler. 10″.