Wilo 4105032 Star S 21F Three Speed Wet Rotor Hydronic Circulating Pump, 115-Volt Uses 3/4-Inch - 1-1/2-Inch standard flange. Standard orientation Temperature range 14 Degree Fahrenheit to 230 Degree Fahrenheit 21-feet maximum head with 21 GPM max flow rate Can be installed in any position where the shaft is horizontal Stainless steel shaft