Stainless steel vacuum insulation keeps beverages hot or cold for hours. Durable and sanitary 18/8 stainless steel interior. Wide mouth accommodates full size ice cubes for cold beverage. Compact design takes up minimal space while maximizing capacity Zojirushi's Tuff Slim stainless steel vacuum bottle will keep your beverage hot or cold for hours. This item is elegant, light and compact in design. It is unbreakable with all stainless steel construction. The Tuff Slim also has a wide mouth and an easy to clean sanitary stainless steel interior.