2) Pentek DGD-2501-20 Spun Polypropylene Filter Cartridge, 20" x 4-1/2" by CFS

2) Pentek 155358, DGD-5005-20 Dual Gradient Density Polypropylene Sediment Cartridge by CFS These are compatible filters. This spun polypropylene filter cartridge reduces sand, silt, scale, and rust particles in residential, commercial, and municipal drinking water. It has two separate gradient layers for higher particle reduction efficiency and dirt-loading capacity than standard spun or string-wound cartridges. The nominal filtration rating of the pre-filter layer is 50 microns, and the rating of the post-filter layer is 5 microns. The filter is made of spun polypropylene fibers for resistance to chemicals and bacteria. It has an initial pressure drop of less than 1 pound per square inch (psi) at a flow rate of 20 gallons per minute (gpm), and operates over a temperature range of 40 to 145 degrees F (4.4 to 62.8 degrees C). This spun polypropylene filter cartridge meets National Sanitation Foundation/American National Standards Institute (NSF/ANSI) standard 42 for quality assurance, and is used for treatment of residential, commercial, and municipal drinking water. Specifications Nominal filtration rating (pre-filter) 50 microns Nominal filtration rating (post-filter) 5 microns Initial pressure drop at 20 gpm <1 psi Temperature range 40 to 145 degrees F (4.4 to 62.8 degrees C) Maximum dimensions (H x W) 20 x 4-1/2 inches (508 x 114 mm) Materials certification NSF/ANSI standard 42 The nominal filtration rating is for a particle removal efficiency of 85%. H is height, the vertical distance from lowest to highest point; W is width, the horizontal distance from left to right; D is depth, the horizontal distance from front to back.