This is an authentic OEM part from Briggs and Stratton, Troy-Bilt, and Snapper for use with Pressure Washers. The Briggs & Stratton Pressure Washer Pump Saver prevents harmful buildup of hard-water mineral deposits in the pump, maintains pump seals and pistons and promotes longer pump life. It contains anti-freeze to protect the pump from...Read more freezing and provides safe winter storage. This part is sold individually. No mixing, stirring or shaking is required. Just attach the pump saver to the pump and dispense.