Drink at your own pace: The IonMug Heated Coffee Mug Warmer & Charging Coaster features a built-in rechargeable battery that can keep your beverage perfectly hot for up to 3 hours, or leave it on the included charging coaster instead to keep it hot all day. Wash away: Made with 304 stainless steel and ABS material, the ion Mug can easily be cleaned under running water. No worries: The 12oz. ion Mug will turn off automatically after 3 hours, or if no liquid is detected in the mug.