Replace the filter in your Eau Good water bottle with this recharge refill. Made from the branches of trees, binchotan charcoal is an active carbon that works by absorbing contaminants such as chlorine, and releasing nutrients into your water. Also, it helps to neutralise pH levels. Refill sticks have a three-month lifespan. At this point, boiling the stick in water recharges it for a further three months.