The Gold Armour GulpBliss 18/8 stainless steel double wall vacuum insulation technology will keep cold liquids chilled for up to 24 hours, while hot liquids remain hot for up to 6. Vacuum Insulation Technology - This bottle has a double-wall exterior with a vacuum seal between the walls. This means your drink temperature has no medium for the heat or cold to transfer through. Your drink will truly stay as hot or cold as long as possible. Retire your coasters and koozies. Even filled with ice or boiling water, this bottle will never sweat or get hot to the touch! Copper Coated Insulation - The exterior of the vacuum sealed area is dipped in copper for added insulation. Copper reduces the transfer of temperature, adding even more insulation to your bottle. Premium 18/8 Stainless Steel - Gulp Bliss insulated water bottles are made of high quality food grade 18/8 stainless steel metal. The bottle is highly rust resistant and it will not retain flavors from previous drinks like plastic bottles will. All Gulp Bliss bottles, tumblers, and lids are BPA free. Hand wash only. Built to Go the Extra Mile - Enjoy the protection and color that rugged powder coating adds to the bottle. The powder coating is sleek and durable, making it the perfect travel companion. Refill, Reuse, Refresh - Keep your cool over and over again. No more one-use cups, no more toxic plastics. We use only food grade, Bpa-free, recyclable materials. Awesome. Guaranteed. Narrow Standard Mouth Opening - The narrow mouth opening on the Gold Armour GulpBliss water bottle makes for easy drinking and less sloshing and large enough to fit most ice cubes. The opening is internally threaded, giving a smoother bottle lip to drink from.