The 2400-WB circulator is designed specifically for use on unpressurized outdoor wood boiler applications. Features include a quiet running, close coupled, thermally protected motor assembly with permanent split capacitor and permanently lubricated bearings. A stainless steel shaft, silicon carbide mechanical seal and non-ferrous impeller make the Wood Boiler Series Circulator an ideal choice for years of maintenance free operation. Compact, space saving design - Powerful close-coupled, maintenance free motor - Superior efficiency, high starting torque - Permanently lubricated, sealed for life bearings - Rugged 1/2" Stainless Steel Shaft - Carbon/Silicon Carbide mechanical seal for long life - Universal flange to flange dimensions; Ideal for retrofits - Dual electrical knock-outs