Pentek PD-5-20 # 155756 PD5-20 Polydepth Sediment Replacement Water Filter Cartridges Compatible With Culligan / Ametek / US Filter / Plymouth / Kleen Plus / American Plumber / Bruner & Many Other Brands. Polydepth 5 Micron Sediment Water Filter. 20" long X 2 1/2" diameter. 20 per case, sold individually. Ametek # 155756 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.