4PCS Water Filter Replacement for BERKEY Black Activated Carbon BB9-2 Filters for Gravity-Fed Water Filter System Filtration precision up to 1 Micrometre: This filter uses high-quality coconut shell activated carbon as the filter material, providing filtration precision up to 1 micrometre. Effectively removes impurities such as sand, rust, sediment, and odor, while reducing chlorine with a removal rate of more than 99%. Compatible Models: Designed to replace filters for gravity-fed water filtration systems including Travel, Grand, Royal, Imperial, and Crown Series. Precision-designed washers and wing nuts ensure a secure fit and help prevent leaks. No primer required; install and use immediately after replacement, reducing initial flushing time. Durable Lifespan: For 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 maintain the siphoning action of the drip system. Note: Before installation, soak and rinse the filter thoroughly to remove fine particles from manufacturing. Color: Black Material: Coconut shell activated carbon Package Contents: 4 x Water purification filter elements Note: The package includes only the items listed above. Other products are not included. Note: Lighting and monitor settings may cause slight variations in color between the product image and the actual item. Measurement may vary by +/- 1-3 cm.