Pentair Pentek ECP Series cartridges are made from a special formulation of resin-impregnated cellulose and polyester fibers. This unique blend provides higher wet strength than regular cellulose cartridges while delivering high flow rates and strong dirt-holding capacity at extremely low pressure drop. The ECP50-BB is the 10-inch Big Blue, nominal 50 micron version and reduces coarse dirt, sand, silt, rust, and other sediment, making it an ideal high-flow pre-filter that helps protect appliances, plumbing, and downstream filters. The pleated media is formed around a polypropylene core for added strength, and the overlap seam is sonically welded to reduce internal bypass for more efficient filtration with minimal unloading and media migration. Big Blue cartridges use molded endcaps with gaskets for a secure seal in the housing. The 10-inch Big Blue cartridge contains 18 square feet of media surface area, and the initial pressure drop is less than 1 psi at 20 gpm. The cartridge is rated for water temperatures from 40 to 125 degrees F. With maximum dimensions of 4.5 inch by 9.75 inch (114 mm x 248 mm), the ECP50-BB is a drop-in replacement for 10-inch Big Blue whole-house housings. The yellow color-coded endcap identifies the 50 micron rating for quick reordering. Replace the cartridge when you notice a drop in water pressure or water quality