Kishu Charcoal To Go is the ideal way to bring filtered water on the go; the gym, the car, your bicycle. Ideally placed in any 12-16 ounce water bottle, Kishu begins working immediately bonding with toxins in tap water. We recommend adding tap water in the evening for use the next day. Optimal filtration time 1-2 hours. Bonds with toxins like lead. Enjoy the taste of natural spring water with Kishu Charcoal. To renew, simply boil gently in a shallow pan of water for 5 minutes, allow to dry out for 20 minutes before reusing. One stick lasts 4 months.