Abstract: Two perforated metal sleeves are secured in radially spaced coaxial relation one within the other between a pair of rigid end caps that are releasably secured to opposite ends of a plurality of rods which support the caps removably and sealingly over opposite ends, respectively, of the sleeves. An annular filter cartridge is releasably secured in the radial space between the sleeves with resilient annular end caps on opposite ends of the cartridge disposed in releasable, sealing engagement with the rigid end caps. Fluid that is to be filtered is delivered to the radial space separating two annular filter elements in the filter cartridge. When one or the other of the end caps is removed from the support rods the cartridge can be removed from between the sleeves and replaced without having to destroy the sleeves or the rigid end caps.