Stainless Steel Material: Our recirculating pump is constructed with a heavy-duty stainless steel pump head, aluminum pump housing, and PES impeller, rust-proof, waterproof. Brass fittings and water-stop will come with the pump for corrosion-proof and leakage-proof. Note: The brass adapter has a 3/4 G thread diameter and is compatible with 1/2 NPT. Large Flow & Quiet Running: Powerful circulator pump has max. 40 L/min water flow, max. 10 bar pressure and max. 20 ft head lift. In addition, super silent running property(about 25dB) can provide you with a quiet pump: high performance but low noise. Adjustable Speed Switch: This water circulator pump features a three-power control switch in 46/67/93W. It is convenient for you to adjust the flow rate as your different requirements. Easy Installation: Our circulating pump for hot water can be used directly to drinking water pipelines with a wrench, fitting with an NPT 3/4' inlet/outlet hose