Carvin SERIE'S FEATURESRing-Lok access to filter element for "tool-free" servicing.Built-in tooth on Ring-Lok allows you to easily disengage lid.Automatic Air Bleed assures 100% filtration and longer filter cycles.Coreless elements allow easy cleaning from inside-out with a garden hose.2" (51mm) drain to assure easy draining and winterizing.Drain port may be used as alternate inlet allowing flexibility during installation.Available in 330 (30,7m2), 440 (40,9 m2) and 550 p