If you've spent even just a little time driving the vehicle that's towing your marine craft, you know that it's not always an easy task. Keeping both your vehicle and your trailer under control is critical. To do that, you need reliable brakes on your trailer. A brake master cylinder, which is sometimes simply called the master cylinder, is a hydraulic pump that feeds brake fluid into the brake circuit to convert the pressure you put on the brake pedal into hydraulic pressure. This particular model of master cylinder can be used with either disc type brakes or drum type brakes. Because it was designed with marine applications in mind, it has an all-aluminium construction, which resists corrosion from exposure to water. It also has a reverse valve drain tube, so that you can connect it to the electric reverse solenoid, which redirects the fluid that would ordinarily be going to the trailer brakes back to the master cylinder. This disc brake master cylinder is compatible with UFP hydraulic disc brake actuators A-60, A-75 & A-84