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%. [Compatible Models]: This filter is compatible with gravity-fed water filtration systems including Travel, Grand, Royal, Imperial, and Crown Series. The precision design of 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. No low flow issues. [Durable Lifespan]: To extend the life of your system and maintain optimal performance, replace the filter every 6,000 gallons (depending on tap water quality). Fully submerge the carbon filter once a week to ensure proper siphoning in the drip system. [Note]: Before installing the filter, soak and flush the filter to remove residual manufacturing particles. Color: Black Material: Coconut shell activated carbon Package Contents: 4 Water Purification Filter Elements Only the above package content is included; other items are not included. Note: Light reflection and different display settings may cause slight color variations between the product image and actual item. Measurement may vary by +/- 1-3 cm.