FILTER UNIT

摘要

A filter unit includes a substantially cylindrical body portion having a proximal end and a distal end. An engagement protrusion extends from the proximal end of the body portion. A laterally extending key member is disposed on the body portion. At least one engagement surface traverses at least part of the body portion. The at least one engagement surface includes a first segment that extends substantially parallel with the longitudinal extent of the body portion. A second segment extends at an angle relative to the longitudinal extent of the body portion. A third segment extends at a different angle than the second segment.