This is ( 6 pack) MatriKX MATRIX MKX-B10-RFL 20 Micron Radial Flow Carbon 4.5″x10″ Carbon Block 20 micron Cartridge, specifically designed for high flow while improving taste / removing odors FROM UNTREATED WATER. Carbon made from Coconut has superior qualities to standard carbon cartridges. Less channeling which means less by-pass. Note that the ‘activated carbon’ process works when the carbon particles touch the water. Fine silt/mud will coat the carbon and render the cartridge largely ineffective. When fittings always re-lubricate the sump o-ring and threads, to enable easy sealing from hand tightening the sump. This reduces stretching & flattening of the o-ring. Always purge before finishing your systems cartridge change, to avoid unnecessary air spurting through your household taps. Sumps tighten from the effect of water pump pulsation.Specifications:Gaskets: NBRPressure Drop: 1.0 PSIMicron Rating: 20 micronsTemperature Range: 40 – 180 FFilter Life: About 20,000 gallonsDimensions: 9 3/4″ length x 4 1/2″ widthFilter Media: Coconut shell GAC carbon blockRemoves/Reduces: Chlorine taste and odor, dirt, sediment, rust, etc.Flow Rate: 3 gallons per minute @ 1.0 PSI (may vary depending on specific water filter system)