Ergonomically designed, fit most vehicle cup holders. 12V stainless steel car heating cap sits snugly in your car cup holder and plugs into the cigarette lighter to keep your drink warm. Heat function and practical, maintains a temperature of 65 C. No batteries required, just plugs in to your dashboard lighter. Note: The input power of this product is 60W (12V / 5A). Please confirm that the output voltage of the cigarette lighter is 12V and power of the cigarette lighter is greater than 60W before purchase, otherwise it will stop working due to the overload protection of the cigarette lighter. Quality Guarantee: Warranty period : 18months (Promise no reason to return and exchange within 180 days).