Our Extreme Max Universal Motor Flusher is a must have tool for winterizing and off-season maintenance for your boat. You simply attach a garden hose to the motor flusher and attach it to the water intake. The rubber cups slip over the side water inlets on most inboard and outboard lower units. This allows you to flush away sand, silt, salt, and alkalis, preventing clogging and corrosion while extending your engine's life. Plus, you will also have the ability to run your engine safely at home in your driveway.