Replacement for discontinued 47-22270 cartridge. 20 carbon block filter. The 3M CUNO 20 47-9224 Carbon Block Filter Cartridge is a replacement water filter cartridge that reduces contaminants from your water. This carbon block water filter reduces sediment and the taste and odor of chlorine to make water clearer and better tasting. This 20 inch carbon block filter replaces the 3M CUNO 47-22270 and is very effective.