Pentek ECP20-BB # 255491 ECP20BB Big Blue Sediment Water Filter Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands. Big Blue 20 Micron Pleated Cellulose-Polyester Sediment Water Filter. 10" long X 4 1/2" diameter. 8 per case, sold individually. Ametek # 255491 Culligan CP-5BBS use as ECP5-BB (255490) ECP Series cartridges are manufactured from a special formulation of resin-impregnated cellulose and polyester fibers. This construction provides high flow rates and dirt-holding capacities, while maintaining extremely low pressure drops. The media is pleated around a polypropylene core for added strength and the ends are immersed in a thermo-setting vinyl plastisol. Embedding and sealing each end of the pleat block in this fashion fuses the components together forming a unitized end cap and gasket. Order a case and save even more.