This 500ML Electric In-Car Travel Heated Mug is powered by a 12V cigarette lighter plug power source that enables you to drink hot water on the road. The cup's interior and exterior are equipped with vacuum insulation technology that provides good insulation to prevent burns. Its sealed kettle cover made by high-quality silicone gel is safe, non-toxic, and displays good sealing performance to keep water warm and that drink does not spillover. Designed with an indicator light, you can understand the working state of the electric cup. Fits most car cup holders & great for travel use.