Check the listing for details. Pentek DGD-2501-20 Dual Gradient Density Filter. Color: Blue, Condition: New. Listed at 36.30 USD. The Pentek DGD-2501-20 replacement dual-gradient density filter is a 2-in-1 filter that works as both a pre- and post-filter, eliminating the need for step-down filtration systems in your home. The outer-layer acts as a sediment filter with 25 micron particulate reduction, and an inner-layer with a 1 micron rating that further improves water quality. The pure polypropylene construction has a strong resistance to chemicals and corrosion. This 20" water filter is also known by part number 155360-43. Pentek DGD-2501-20 Dual Gradient Density Filter specifications: Part Number: DGD-2501-20; 155360-43Service Life: 8,000 gallons; 3-6 months Operating Temperature: 40 -145 F Flow Rate: 20 GPM @ < 1 psi Dimensions: 4-1/2"x20"Micron Rating: 25 pre-filter; 1 micron post-filterReduces sand, dirt, silt, rust, scale particles Filter life varies depending on usage and water qualityFor more information, view the product manual The Pentek DGD-2501-20 replacement fits the following filter housings: Ametek, US Filter, Culligan 20" Big Blue housings Standard size 20" filter housings with a 4-1/2" diameter