Consisting of dual stainless steel corrosion-resistant layers, the Acera Harmony Collection advanced travel mugs have a patented ceramic core. Made of Tourmaline crystals, this ceramic liner actually enhances the flavor of your drink. It combines the durability and temperature control of steel with ceramic, which is great for drinking acidic beverages like coffee, tea, and juice. What’s more, the ceramic core doesn’t absorb or impart flavors—like stainless steel can—so your drink tastes just as it should. And the bottle itself has a honeycomb exterior for a gorgeous look and comfortable grip. It’s not all about looks, though. The Harmony Collection Mugs triple-wall construction is great for both cold and hot drinks, maintaining its temperature for up to six hours. Ensure you get the highest quality possible from your beverages with these advanced travel mugs.