Product Description Safe material: The filter uses natural coconut activated carbon, ensuring excellent reduction performance that will not leach contaminants back into your water Long-lasting service life: To prolong the life of your appliance and achieve optimum performance, we recommend you replace the BB9-2® filter every 6,000 gallons per pair, which will vary based on water conditions. Perfect fit: Replacement for BB9-2® Replacement Filter and fit the water filter system working in pair with PF-2 filter. Includes 2 priming buttons. An accurate design promises a perfect fit with the original brand without leakage. This filter is not sourced by or sponsored by Berkey®. The manufacturer’s name has been used for reference purposes only. AQUA CREST is an independent brand. Easy to install: For detailed instruction, please kindly refer to the Instruction Manual in the box. Compatible models: Interchangeable with Travel, Big, Royal, Imperial and Crown Series.