The 106285MF-743 Armstrong S-57-1 Bronze Pump 3/4HP 1PH ECM MotorĀ is part of theĀ Armstrong Series S & H series circulating pumps. In-line circulators are suitable for applications such as hydronics heating and cooling, domestic water systems, multi-stage zoning and general industrial service. Both bronze fittet and all bronze models are available in a wide range of sizes to match the performance requirements of any of these applications. Armstrong Series S & H circulators are durable and trusted products that have been used by HVAC professionals for decades.