Patent ID: 8425773

Claim:
A filter assembly comprising a first and second filtration element adapted to be interconnected in end-to-end relationship wherein each filtration element comprises: a fluid filtration media, a housing, and an end cap which comprises an annular surface co-extensive with the housing and an outer face adapted to engage with an abutting outer face of an end cap of an adjacently positioned filtration element; wherein each end cap comprises an inner and outer hub connected by a plurality of spokes and a locking structure for preventing relative axial movement between the first and second filtration elements once engaged, wherein the locking structure comprises a plurality of projections extending radially inward from the inside of outer hub of one end cap, and a plurality of corresponding receptacles on the other end cap which are adapted for receiving the projections, wherein the locking structure is reversible engaged by abutting the end caps of the first and second filtration elements and rotating one element relative to the other; and wherein the filter assembly is characterized by: the first filtration element comprising a depressible tab located on the annular surface of the end cap which is movable in a radial direction between a first and second position; and the second filtration element comprising a slot located on the annular surface wherein the slot is adapted to receive the tab when the first and second filtration elements are engaged such that relative rotational movement between the first and second filtration elements is prevented while the tab is in a first position within the slot, but where such relative rotational movement is permitted when the tab is in a second position.