Size M corresponds to a palm width of 11cm and a middle finger length of 8cm. A size XL corresponds to a palm width of 12cm and a middle finger length of 8.5cm. Please choose according to your actual palm size Heated Ski Gloves provide a wide heating area covering the entire back of your hand and all fingers in case of poor blood circulation, arthritis, cold weather, or just for extra comfort and warmth. Unique five-finger and back-hand heating layout, fast heating from fingertips to palm, threaded wiring design, soft and delicate, prevent pulling Connect the battery to the connector in the connector gloves, put the battery in the battery bag, zip it up, approx. After 5 minutes, the inside of the glove is heated up to a maximum of 55 degrees. The flexible heating fiber is integrated with the inside of the glove to form a whole, which has a good heating effect, effectively prevents heat loss, and transfers more heat to the inside of the glove. The hand feels comfortable and not stiff. Waterproof treatment: The surface of the glove is made of water-repellent fabric, which is waterproof and windproof and error-proof. The zipper is coated with waterproof treatment, which has good waterproof effect, no tearing, good smoothness, smooth and delicate surface, and has a smooth leather-like feel. Note: This product does not contain batteries or power banks