This protects your pressure washer pump and other internal components, like the pistons and seals during storage season. It also provides anti-freeze protection, so you no longer have to stress about that pump freezing. Not only that, but provides great lubrication for all the moving parts and prevents the buildup of harmful water mineral deposits. STA-BIL experts recommend attaching the hose on the Pump Protector can to the inlet on the pressure washer (where the water hose connects). Next, press the button on the can to disperse the fluid into the pressure washer, once fluid begins to exit the pump, it is now protected. Remove the hose and store your pressure washer.