Iron Flask is Here to Insure You Have the Hydration Needed to Get You Through the Day and Crush it! #yougotthis. Features 18/8 Stainless Steel and is vacuum insulated to keep your tumbler condensation free. The powder coated exterior finish offers durability and an easy grip. Each tumbler is packaged in a color matching gift box. To keep your tumbler and message in the best possible shape we recommend to hand wash in warm soapy water.