Features: 1) Built-in far infrared heated fiber cloth 2) Built-in storing heating material. 3) It can be used on the stadium,campaing,fishing,hunting,and anywhere you like. It is no need the battery. 4>It is only 0.8kg,can be take any where easy. 5>12V, using car cigarette lighter as the charger, charging around 20 minutes to store the heat, and than it can be lasted heated for two to four hours.