Made of 100% Natural Golden Bamboo. 100% Eco-Friendly, Bio Degradable. No chemical used. Totally Handmade Product.  Enjoy each Sip of coffee or tea with bamboo fragrance  Natural bamboo water cup, environmentally friendly, with bamboo fragrance. How to store the cup: Wash, dry and place in a dry and ventilated place. Due to the natural hand-made, the weight and size of each cup are different, please consider carefully!  Outer side polished with natural shellac for shining and waterproofing. Nothing used inside to keep natural condition.  Useable Washable and Durable. If found fungus, please keep in sunlight for 2 – 3 hours and clean with dry cloth. Think past, feel past. A grate feels of human civilization when didn’t invented metals. They just used stones woods and bamboos. At the beginning of civilization, human used these types of Utensils. It is the Oldest Utensils of Asian Age. Say NO to plastic polymer and chemicals. Love Natural Handmade product.