Hypro has developed a piston pump that is versatile to help you tackle whatever job you face. The Big Twin® piston pump is just as effective in high pressure washers as it is as a sprayer pump. It can be used with water, cleaners, insecticide or other chemicals, fertilizer, and other agricultural or industrial fluids. Suitable for up to 400 PSI, Hypro's piston pump is as capable as pumps come.