【Wide Compatibility with Berkey Systems】Perfect replacement for Berkey BB9-2 Black Filters and PF-2 Fluoride & Arsenic Reduction Elements, fully compatible with Berkey Big, Travel, Royal, Imperial, Crown, Light series gravity water filtration systems. Precise design ensures tight fit to prevent water leakage for seamless use. 【High-Efficiency Full-Range Purification】BB9-2 black carbon filter effectively removes heavy metals, sediment, rust, deposits and 99% residual chlorine while enhancing water taste; PF-2 white fluoride filter uses natural mineral-based medium to efficiently reduce fluoride and arsenic, providing clean and healthy drinking water at all times. 【NSF 42 Certified Safe Materials】Officially NSF 42 certified. Berkey replacement black carbon filter features premium natural coconut shell activated carbon, and fluoride filter uses natural mineral-derived hydroxyapatite. Lead-free & BPA-free filter housings prevent contaminant leaching, ensuring family drinking safety. 【Long Durable Service Life for Filter Elements】For optimal filtration performance, replace 1 pair of BB9-2 black carbon filters every 6000 gallons and 1 pair of PF-2 white fluoride filters every 1000 gallons (varies by local water quality). Note: Submerge carbon filter fully once a week for proper siphoning of the drip system. Easy Use & Risk-Free Purchase：Rinse all Berkey replacement filters with faucet water for at least 1 minute before first use to wash away loose powder. TDS levels do not fully reflect water quality—our filters target harmful impurities (not beneficial minerals) and thus do not reduce TDS values. We offer free replacement or a full money-back guarantee for unsatisfactory purchase, with professional after-sales support available anytime. Gravity Water Filter Replacement for Berkey