Whole-house and undersink filter cartridges are made with different types of media, and each one does a different job. Start with what you want to remove from your water, then shop by size.
This collection carries cartridges from Pentek, American Plumber, GE SmartWater, 3M Aqua-Pure, Omnipure, Purtrex, Culligan, Watts, and Tier1, mainly in 10 x 4.5 and 20 x 4.5 inch sizes. If you already know your size, the size-specific collections are the fastest way to shop: see 10 x 4.5 Inch Replacement Filters and 10 x 2.5 Inch Replacement Filters.
Many homes use both: a sediment filter first to catch particles, followed by a carbon filter for taste and odor. Running sediment first also helps the carbon stage last longer.
Not sure which media you need? Call 1-800-277-3458.