Double Wall Stainless Steel Water Bottle 18/8 inner and outer. Capacity 650ml. Powder coated non slip finish. Designed to be portable durable and fashionable. It is made of 18/8 stainless steel. the highest quality steel used for food preparation giving the flask lifetime durability and eliminating the need for plastic and glass making it the ultimate eco-friendly liquid bottle. The double-wall has been developed to keep hot drinks warm for up to 8 hours and cold drinks cool for up to 18 hours. The leak-proof lid is the ultimate combination of wide mouth convenience and narrow mouth drinkability. Perfect for active/sport use this lid allows you to sip pour or chug your beverage (without moving the entire lid).