Laing LHB08100095 E3-BCTVNN1W-11 E3 Series Circulator with 1/2-Inch Threaded 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.)