Check the listing for details. Waterdrop Alkaline Water Filter Berkey for BB9-2 Purification Elements - 1-Pack. Color: Black, Condition: New, Made in United States. Listed at 32.00 USD. This Waterdrop Alkaline Water Filter Berkey BB9-2 is the perfect addition to your Aqua Optima Evolve system. It comes with two packs of purification elements that use carbon/charcoal filtration method to provide you with clean and healthy water. The black color and sleek design of this cartridge make it a stylish addition to your home or office. This filter is compatible with both Aqua Optima and FilterLogic brands, and is made of high-quality materials such as stainless steel, ceramic, and steel. With an item height of 9 inches, it is easy to install and use. Get your hands on this Waterdrop Alkaline Water Filter Berkey BB9-2 and enjoy the benefits of pure and refreshing water.