Radial flow design. Produces a substantial output at relatively low RPM's. Low noise level make excellent for use in heads & galleys. Massive 3" diameter motor idles at 3100 RPM's assuring long life. Housings are molded of tough glass filled composite resin.Flange Mount # 54124 - Conventional design outlet flange to mount directly to the exhaust opening in the hull. Molded mounting brackets simplify installations. Remote Mount # 54154 - 3" ducts attach to both the inlet and the outlet and readily adapt to new or existing vents and collector boxes. Brackets are molded in.