1 & 3 Stage Replacement Filter Set for RO1000: This F4RO1000 replacement filter pack includes 2x FCF1000 composite filters, 2x FPC1000 carbon filters — engineered to work seamlessly with iSpring RO1000-BN/RO1000-ORB 1000 GPD tankless reverse osmosis systems High-Efficiency & Long-Lasting: Under normal use, each FCF1000 and FPC1000 filter cartridge has a lifespan of 10-12 months. This kit can last 20-24 months, depending on your incoming water quality and water usage, ensuring your home or business has clean, great-tasting water for the long term Advanced Filtration Technology: The FCF1000 filter removes sediment, rust, and chlorine, while the FPC1000 filter further enhances the quality and taste of the drinking water Easy Maintenance, Tool-Free Replacement: The twist-and-lock filter design enables quick and simple replacement without shutting off the water supply. Enjoy hassle-free filter changes and maintain optimal performance with minimal effort Fast and Effective Water Filtration: The iSpring RO1000 reverse osmosis water filtration system produces up to 1000 gallons of filtered water daily. With an impressive flow rate of up to 0.7 gallons per minute, it is the perfect choice for various settings such as schools, offices, small businesses, and homes. Experience swift and dependable water filtration that meets your needs with ease