The small and complex pore structure of Doulton� ceramics makes them an ideal filter medium for drinking water. High Efficiency Filter: Capable of removing more than 99.99% of pathogenic bacteria, particles and disease causing cysts such as Cryptosporidium and Giardiameter Long Life/Value for Money: The outer shell of Doulton� ceramic drinking water filters may be cleaned to prolong the life of the product, meaning the filter can be re-used rather than replaced, giving a much longer life-span and saving you money. On average, the filter candle will remain effective for at least 6 months (depending on usage) before it will need to be replaced. Anti-Bacterial Action: Contains a proprietary system to inhibit microbiological growth, meaning that there is no need to sterilise the filter. Retains Essential Minerals: Allows essential minerals to remain in the water which benefits your health. No Power Required: Does not require electricity to function so cost-effective to run, not vulnerable to interruption of power supplies and can be used when no power available. Bottled water quality on tap on your boat No power required - low running costs Eco-friendly, reusable filter cartridges 175 years experience - a proven brand you can trust Long-life filters - great value for money Simple to install, use and maintain