2 Black Berkey Replacement Elements & Black Berkey Primer The Black Berkey PrimerTM is a hand-powered priming pump that makes it possible to prime Black BerkeyTM Elements easily, without the need for faucets or hose connections Priming the Black BerkeyTM Elements saturates the filters with water prior to their use, allowing for clean water production anywhere. The Black Berkey Primer is the easiest way to prime Black Berkey Elements. Please note this primer is only for Black Filters. Includes: Set of 2 Berkey BB9-2 Replacement Black Purification Elements & Black Berkey Primer Each black element has a life of 3,000 gallons, or 6,000 gallons for the pair. (less than 2 cents per gallon of water)