Slimline 20" Accepts ALL 2.5" x 20" filters 3/4" Female Ports Allows for high flows and simple connection to existing plumbing with any 3/4" male NPT fittings (see "Related Products" for fittings) Mounting Holes Allows for easy connection to mounting brackets with 1/4" lag bolts or screws (see "Related Products" for fittings) Bracket Requires bracket designed for slimline housings with 3/4" ports. The brackets used on standard housings with 1/4 & 3/8" ports and with the Big Blue housings will not work with this housing. See bracket series BRK-25P for the brackets that fit these housings. Housing Only DOES NOT include filter cartridges, brackets, fittings, housing wrench, or mounting screws. Find these items in under the "Related Products".