We have taken our best-selling boulder bottle and added features that make it better than ever. Eco Vessel boulder insulated Water bottle is our flagship thermal hydration vessel that will keep your beverages hot or cold all day long. Made from food grade 18/8 stainless steel and featuring our signature trimax triple insulation Technology, it's vacuum insulated and tested to keep Iced liquids cold for up to 40 hours and hot for up to 12 hours.