The perfect coffee starts with the perfect filter. Cone shape ensures uniform extraction for pure coffee flavor. Thicker (20 - 30% more than the competition) fiber filter design keeps bitter elements, oils, and grounds in place and out of your cup. Pre-folded for convenience. Oxygen cleansing is a bleach-free process, ensuring no chemical residue or taste is imparted to the filter. Fits all CHEMEX Coffeemakers except CM-1, CM-1C, CM-1GH.