Universal Reverse Osmosis Water Filter Set: Compatible with most 10" standard under the counter reverse osmosis water systems, such as APEC ROES-PH75, RO-90, RO-45, RO-0, RO-PERM, RO-PUMP, ROES-PHUV75, ROES-UV75-SS, ROES-UV75 and others, offering broad compatibility and seamless integration with your existing system. 1st Stage Sediment Filter: Certified by NSF International to meet NSF/ANSI Standard 42, this 5 micron filter features three gradient density layers to effectively remove 99% of rust, sediment, and particles. As the first line of defense in a reverse osmosis system, it prevents clogging of subsequent filters and helps protect the entire filtration system from damage. 2nd & 3rd Stage Carbon Filter: 5 micron extruded carbon block filters made from BPA-free activated coconut shell carbon with a highly porous structure, NSF 42 certified. Effectively removes chlorine and volatile organic chemicals, enhancing water taste while prolonging the lifespan of the reverse osmosis system. 4th Stage Reverse Osmosis Membrane: The 75 GPD RO membrane is engineered with a density-graded 0.0001-micron TFC filtration layer, achieving a high 97% stabilized salt rejection rate. It effectively removes over 99% of tough contaminants like dissolved solids, microplastics, heavy metals (including fluoride, calcium, magnesium, and lead), as well as organic materials and other harmful minerals. Independently tested to NSF/ANSI 58 standards. 5th Stage Post-Carbon Water Filter: T33 inline carbon filter made of food-grade, BPA-free activated coconut shell carbon with a highly porous structure, it has a built-in 1/4-inch (JG) quick connect fitting for quick connection on both ends. As the final stage of filtration in the system, it removes any residual contaminants and enhances the taste of your drinking water to make it fresher and more refreshing. Includes: (1) 5 micron sediment filter, (2) 5 micron carbon water filters, (1) 75G RO Membrane, (1) T33 post carbon filter SimPure 5-Stage Reverse Osmosis Replacement Filter Set with 75 GPD RO Membrane, SPC4-RO75