This stainless steel cup plugs into your car's cigarette lighter and maintains a temperature of 75 degree - keeping your tea or coffee warm and drinkable while you're on the travel. Stainless steel 12V Car Mug sits snugly in your car cup holder and plugs into the cigarette lighter to keep your drink warm as you go! Features: 100% brand new， ergonomically designed， fit most vehicle cup holders. Heat function and practical， maintains a temperature of 75 degree. No batteries required， just plugs in to your dashboard lighter . Avoid direct contact with liquid on the plug adaptor. 12V car mug does not re-heat cold drinks. Not suitable for dishwasher use， wipe clean with damp cloth. Available color: Silver. NOTE: maintains a temperature only， can not boil water.