Pentair WhisperFlo High Performance 1 hp Pump WF-24 is best known for it's smooth flow and its ultra-quiet operation. Whisperflo pool pumps are built to withstand the test of time. Thermoplastic housing protects the sensitive parts from extreme heat and corrosion. How does the pentair Whisper flo switch speeds so smoothly is a question often pondered. The new motor never needs lubrication and uses very little energy. Featuring a threaded shaft and durable commercial duty 56 frame motor with NEMA square flange, this motor increases pump efficiency, and productivity for a long life of effective service. Pentair's Whisperflo pool pumps are ideal for pool and spa combinations, and for operating in-floor cleaning systems. The Whisperflo pool pump is 40 percent glass-filled thermoplastic with the user-friendly cam and ramp "see thru" lid that's simple to take off and check. FunnelFlo diffuser and impeller minimize unwanted turbulence and noise.