The Pentair Pentek DGD-7525-20 is a dual-gradient density sediment filter in the DGD Series, engineered for whole house water filtration in standard 20-inch Big Blue housings. Manufactured from 100% pure polypropylene, it will not impart taste, odor, or color to your water while providing dependable chemical compatibility. The 25 micron rating captures dirt, sand, silt, and other particulates and helps protect downstream filters, appliances, and plumbing. The dual-gradient density design progressively increases filtration from the outer surface to the inner core, combining pre-filtration and final filtration in a single cartridge. This delivers up to 3X the dirt-holding capacity of similar size sediment cartridges and greater capacity than standard spun or string-wound filters. The increased effective filter depth of 233% provides high particulate reduction efficiency at less than 1 psi pressure drop at 20 gpm, making the DGD-7525-20 an ideal high-flow pre-filter for high-demand applications. Fits all 20" x 4.5" Big Blue and heavy duty filter housings. NSF/ANSI Standard 42 certified for material requirements. Suitable for residential, municipal, rural, and commercial applications. Operating temperature: 40-145 degrees F. Replace every 6 months or when water pressure or quality decreases.