Pentek PD-25-20 # 155758 PD25-20 Polydepth Sediment Replacement Water Filter Cartridge Ametek / US Filter / Plymouth / Pentek / Culligan / Kleen Plus / American Plumber / Bruner / Many Other Brands Compatible PD-25-20 Polydepth 25 Micron Sediment Water Filter. 20" long X 2 1/2" diameter. 20 per case, sold individually. Ametek # 155758 The New POLYDEPTH™ filtration cartridge is constructed of quality polypropylene filter media to ensure high efficiency in the inner layer. The polypropylene filter media is thermally bonded and incorporates a rigid polypropylene center core for increased durability. This thermal bonded micro fiber construction offers no fiber release, consistent flow rate and superior filtration performance. It also produces a rigid cartridge that is less subject to collapse than any wound or pleated cartridge, yet is not brittle or prone to breakage problems common with resin-bonded cartridges. Also, the polypropylene construction provides superior chemical resistance and is not prone to bacterial attack. Order a case and save even more.