Pentek CC-20 # 155138 GAC Carbon Replacement Water Filter CC20 Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands. Granular Activated Carbon Water Filter. 20" long X 2 7/8" diameter. 6 per case, sold individually. Ametek # 155138 CC Series granular activated carbon cartridges are an excellent choice to reduce unwanted taste, odor, chlorine and certain VOC's from potable drinking water. They contain coconut shell based activated carbon, which produces drinking water of exceptional taste and quality.