SHURFLO's Revolution™ fresh water pump design was created with a unique one-piece diaphragm and internal by-pass, assuring long life and top performance in all plumbing systems. Designed as the next legendary pump to exceed the expectations of our customers, the Revolution™ Pump is constructed for high flow demand, low noise and no rapid cycling. Shurflo's quality reputation has been built on the reliability and dependability of every pump we build. The 4008 Revolution™ fresh water automatic demand pump is super quiet, thermally protected and can run dry without damage. Mounts in any position. Self-Priming Internal Bypass-Low Cycling Runs Dry ‚Äì Thermally Protected Built-in Check Valve