Pentair Challenger® 355672 Standard Power End Sub Assembly for CH-N1-1F, 1 1 per 2A Challenger High Pressure Pump - The Pentair Standard Power End is a replacement for the Challenger High Pressure Pump. The Challenger Pump components are made from custom-molded thermoplastic for superior strength and durability. The power end is easily installed and removed for service or winterizing without disturbing piping or pump support base.