The Pentair Pentek ECP20-20BB is a 20-micron pleated sediment filter cartridge designed for whole house water filtration in standard 20" x 4.5" Big Blue housings. The filter media is constructed from a blend of resin-impregnated cellulose and polyester fibers, providing higher wet strength than standard cellulose cartridges. The pleated design delivers 36 square feet of filter surface area, extending dirt-holding capacity and filter life compared to non-pleated alternatives. The ECP20-20BB features a sonically welded overlap seam that reduces internal bypass for improved filtration efficiency. The cartridge is built around a polypropylene core for added structural strength, with polypropylene endcaps and gaskets for a secure seal. It is compatible with both chlorinated and non-chlorinated water supplies. This cartridge operates at less than 1 psi pressure drop at 20 gpm, with a temperature range of 40-125 degrees F. The blue endcap is color-coded for quick 20-micron identification during filter changes. Replace every 3-6 months or when you notice a decrease in water pressure.