4PCS Water Filter Replacement for BERKEY Black Activated Carbon BB9-2 Filters for Gravity-Fed Water Filter System P20250110581 [Filtration precision up to 1 Micrometre]: For excellent filtration performance, this filter uses high-quality coconut shell activated carbon as the filter material, with a filtration precision up to 1 micrometre. Efficiently removes impurities such as sand, rust, sediment, and odor, while effectively reducing chlorine with a removal rate of more than 99 percent. [Compatible Models]: This filter is compatible with gravity-fed water filtration systems including Travel, Grand, Royal, Imperial, and Crown Series. The precision design of the washers and wing nuts ensures a secure connection and prevents leakage. No primer required; it can be installed and used after replacement, reducing initial flushing time. [Durable Lifespan]: To extend the life of your system and maintain optimal performance, replace the filter every 6,000 gallons (depending on water quality). For proper function, fully submerge the carbon filter in water once a week to allow the drip system to siphon correctly. [Note]: Before installing the filter, soak and flush it thoroughly to remove residual manufacturing dust. Color: Black Material: Coconut shell activated carbon Package Contents: 4 water purification filter elements Note: Light reflection and different displays may cause the color in the image to vary slightly from the actual product. Measurement may vary by 1-3 cm.