... granular activated carbon water filter cartridge GAC is filled with carbon with high iodine rate,the carbon can be coal carbon,coconut carbon,fruit shell carbon,depends ... can remove chlorine,pigment and odors.Filter Media:Activated Coal Carbon/Coconut Shell Carbon/Fruit Shell carbon with high iodine rateGasket:Silicon,EPDM ... diameter:2.5”,4.5” /28mm 20" granular activated carbon filter cartridge