• Product Image - Big-Blue Cartridges by Harmsco

    We manufacture a complete line of 4 1/2" diameter cartridges for both 10" and 20" Big-Blue filter housings. Harmsco Big-Blue cartridges are made with our proprietary blend of Polyester-Plus filter media; they are thermally bonded for added strength; cleanable and reusable in most applications; individually shrink wrapped; and available in 1, 5, 20 and 50 nominal micron ratings.