The Pentair Pentek WPX50BB97P is a 50 micron polypropylene string-wound sediment cartridge built for 10-inch Big Blue whole-house housings. A durable polypropylene string is wound in a precise pattern around a rigid polypropylene core, reducing fine sediment such as dirt, sand, silt, rust and scale particles while maintaining high flow rates with minimal pressure drop. Polypropylene will not impart taste, odor or color and is chemical-resistant, so the cartridge works well on both municipal and well water and with many industrial fluids. The WPX-BB media is a fibrillated polypropylene fiber cord wound for greater surface area and high dirt-holding capacity, with an initial pressure drop of under 8 psi at 30 gpm and a temperature rating of 40 to 165 degrees F. Unlike the WP-BB media, the WPX-BB cartridge is manufactured without any static-reducing agent, making it the preferred choice when start-up foaming is a concern. This cartridge measures 4.5 inch in diameter and 9-7/8 inch long and fits standard 10-inch Big Blue housings that accept 4.5 inch diameter cartridges. For best results, replace the cartridge when you notice a drop in water pressure or water quality, generally every 3 to 6 months depending on incoming water quality. This is a sediment cartridge only and is not a purifier; do not rely on it to make microbiologically unsafe water or water of unknown quality safe to drink.