The Hydro Flask 21oz Standard Mouth Flask is ultra-versatile and highly practical, ruggedly constructed for on-the-trail functionality. The TempShield insulation has been specially engineered to keep contents hot and cold for extended periods of time, with a stainless steel construction for maximum longevity.A practical and versatile bottle from Hydro FlaskSuitable for hiking and everyday useTempShield insulation - keeps contents cold for up to 24 hours, and hot for up to 12 hours18/8 Pro Grade stainless steel - high quality wear-resistant interiorStandard mouthBPA-Free and Phthalate-FreeDurable powder coated finishCapacity: 21oz (597ml)Colour: Stone (Grey)