Fieldsheer Battery Heated Merino Wool Socks Size: XL 28.5-31.5cm Only used once indoors. Delivery to distant locations may take longer due to restrictions on air transport. Product Features: Keeps your feet warm, perfect for winter leisure, outdoor activities, and outdoor work. Specially designed for cold regions, keeping you warm and comfortable in any weather. 3-level temperature adjustment allows for use in various environments. Includes a remote control for turning the power on/off and adjusting the temperature. Rechargeable and economical for repeated use. Machine washable for frequent use. You can adjust the heat level to one of three settings to suit the environment and climate. Equipped with a 3.7V/4000mAh lithium-ion battery, keeping your feet warm for a long time. The MobileWarming® battery is specially designed to provide power for extended periods. A dual USB cable (Type C) is included, allowing you to charge both foot batteries simultaneously. (Charger not included.) You can easily change the temperature using the wireless remote control, as well as operating from the battery itself. The lights on the battery indicate the set temperature and remaining battery life.