Pro-Grade Stainless Steel. Pure and refreshing. Every time. Made with 18/8 pro-grade stainless steel to ensure pure taste and no flavor transfer — and the durable construction stands up to whatever life brings. It's unique double wall vacuum insulation protects temperature for hours. Cold drinks stay icy cold and hot drinks stay piping hot so you can stay refreshed for any adventure. Slip-free powder coating doesn't sweat and is dishwasher safe for easy cleaning and convenience. A sustainable metal water bottle with a clean design, for a better planet. Newly produced Hydro Flasks do not feature a registered trademark symbol next to the logo.