CFA-P - If you have a high level of sediment in your water, (most of New York City and San Fransisco), add a porous plastic sediment prefilter on in front of your countertop water filter. The disposable element removes particles down to 5 microns in size to extend the life of your KDF/GAC cartridge. Includes housing and one element. CFA-P-R - Replacement element. This product ships directly from the manufacturer and may take 1-2 weeks to arrive.