IPPINKA Bamboo Charcoal Water Filter, 3 Sticks Dimensions: 6 x 1.6 inches Porous surface of charcoal acts as a purifier to filter water. Filtering time is approximately 3-4 hours Set of 3 pieces, each can be easily inserted into a pitcher. 1 piece is good for about 1 liter of water. Boil in water for 10 minutes once weekly to sterilize. Each stick lasts for 1 to 2 months of use as water filter. After that, it can be used as a deodorizer or dehumidifier. Material: all-natural bamboo charcoal - Product of Japan