Laing LHB08100096 E3-BCUVNN1W-11 E3 Series Circulator with 1/2-Inch Sweat Union Connections and Cord Saves 68% electricity compared to a standard circ pump Highly efficient ECM Technology Long lasting, silent operation Maintenance free: shaftless and sealless E3 has higher flow for use in larger houses (over approx. 2300 sq.ft.)