PUMP GAURD 16OZ. | Karcher's environmentally friendly pump guard is specifically formulated to prolong the life of your pressure washer. this specially formulated solution will protect your pressure washer from corrosion, premature wear and freezing (down to -25 deg F). it also adds lubrication to your pressure washer's valves and seals to prevent sticking in the future. ordinary anti-freeze is insufficient in this respect and is not recommended.