The water filter cartridge is made of a grooved polypropylene that filters sediment to 5 microns. The filter cartridge core is filled with polyphosphate spheres which provide the essential protection to both tankless and traditional hot water tank systems. This ingredient reacts with naturally occurring calcium bicarbonates in the water supply to form a thin, tight, non-corrosive, passivating film on pipe walls. This film is almost like a glass coating, separating the water from the metal plumbing / hot water system. This system will prevent corrosion and scale build up on all plumbing components and water using appliances which helps to avoid costly maintenance calls. The IPW Industries Inc slow phosphate cartridge has an industry common dimension of 2.5" (width) x 20" (length). Additional Details ------------------------------ Bullet point: 5-MICRON FILTRATION: This grooved polypropylene 5-micron sediment filter provides high-efficiency water filtration, removing larger particles like dirt, sand, rust from hot water. It is designed for whole house water systems and water heaters, ensuring sediment-free water for your household?s hot water needs. With a water filtration capacity of 5 microns, it?s ideal for protecting your appliances plumbing from debris and should be replaced every 4-6 months for optimal performance. Product description: The water filter cartridge is made of a grooved polypropylene that filters sediment to 5 microns. The filter cartridge core is filled with polyphosphate spheres which provide the essential protection to both tankless and traditional hot water tank systems. This ingredient reacts with naturally occurring calcium bicarbonates in the water supply to form a thin, tight, non-corrosive, passivating film on pipe walls. This film is almost like a glass coating, separating the water from the metal plumbing / hot water system. This system will prevent corrosion and scale build up on all plumbing components and water using appliances which helps to avoid costly maintenance calls. The IPW Industries Inc slow phosphate cartridge has an industry common dimension of 2.5" (width) x 20" (length).