It is made from coconut shell based, palm or nut shell based & coal based carbons which creates what many believes to be a sweeter tasting water. Because of the unique pore structure of this carbon, it is well suited for chemical absorption, including VOCS, while reducing chlorine and chemicals that result in taste and odor. The service life of the C-Series Carbon Block water filter cartridge is greatly extended by an outer layer of 10-15µm polypropylene non-woven pre-filtration media and will operate more effectively in most installations than without pre-filtration.