Charcoal filters remove impurities for great-tasting coffee every morning: The quality of the water you put in your coffee machine directly impacts the quality of your morning brew. Koolatron's charcoal water filters feature fine grain organic charcoal in a micromesh pouch for maximum filtration. Universal design is compatible with drip coffee makers and the 12-pack of replacement cartridges lasts up to 1 year. Enjoy better tasting coffee and extend the life of your coffee maker: Municipal tap water is treated with chlorine for your safety, creating by products and residues that remain in your water. Without a filtration system, odours, and unpleasant flavours end up in your coffee. On the other hand, using distilled or very soft water will result in a dull, flat-tasting brew. A charcoal filter in the water reservoir solves this problem by trapping contaminants without affecting the dissolved mineral salts and calcium that are crucial to extracting coffee soluble for fresh, bright-tasting coffee. For best results, replace your filter cartridge every 30 days or 30 brewing cycles and descale your coffee maker using white vinegar or a commercial descaling solution every 2-6 months