The Klean Kanteen Vacuum Insulated Classic 20oz water bottle combines the original, iconic, Classic bottle with high-performance, double-wall vacuum insulation to create a highly versatile bottle. The 20oz Insulated Classic water bottle was designed with high performance in mind, keeping beverages hot for 20 hours and iced for 50 hours. Crafted from high quality, durable food grade 18/8 stainless steel with a wide 1.75 inch (44mm) opening fits ice, is easy to fill, pour and drink from. Electropolished interior and rounded corners make the Vacuum Insulated Classic 20oz bottle easy to clean and maintain. All Klean Kanteen products are made using safe healthy materials and backed by the Strong as Steel Guarantee. Hand washing recommended.