Introducing the FLY RACEDIV Heated Thermal Underwear - the ultimate solution for staying warm and comfortable during the colder months. This innovative product is designed with intelligent temperature control, providing targeted heat to your knees, back, and waist. Powered by any 5V/2.4A USB portable charger, it can start heating in just 30 seconds and has a long duration and heating time. With a 3-level adjustable temperature and safety insulation design, you can easily adjust the heat to your desired level without worrying about overheating.Not only is this heated underwear functional, but it is also designed with comfort in mind. Made from 95% cotton and 5% spandex, it is soft and stretchy, providing a comfortable fit for both men and women. The carbon fiber wire used for heating is safe and durable, ensuring long-lasting use. And for added convenience, this product is machine washable, making it easy to clean and maintain.The benefits of using heated underwear are endless. It helps to improve blood circulation, enhance metabolism, and is especially beneficial for those who suffer from cold sensitivity, Raynaud's disease, arthritis, poor blood circulation, and stiff joints. It is also the perfect solution for various outdoor activities such as skiing, fishing, jogging, hunting, and more.Available in black and gray, and in sizes ranging from S to 5XL for men and XXS to 2XL for women, there is a perfect fit for everyone. To ensure the best fit, we have provided a size recommendation guide based on height and weight. And for those who are close to the critical value, we recommend adding one size for a comfortable fit.Experience the ultimate warmth and comfort with the FLY RACEDIV Heated Thermal Underwear. Order yours today and stay warm all winter long!