Features: Long Lasting: Battery-powered heated insoles for warmth in cold weather Adjustable: Multiple heat settings for personalized comfort Wireless: Lightweight and wireless design for comfort and convenience Wide Application: Ideal for skiing, hiking, camping, and outdoor activities in winter Easy to use: Simply remove your old insoles from your shoes or boots and align them with your new heated insoles to compare sizes and determine if any trimming will be necessary. 1. Actual color may be slightly different from the image due to different lighting conditions 2. Please allow 1-3 cm deviation due to manual measurement Material: Plastic + carbon fiber Charging voltage: 5V 1A Charging current: 400mA 7.4Wh Battery capacity: 2000mAh Load impedance: 8 ohms Heating area: 10 x 6 cm 3 temperature settings: High: 55°C, usage time: 4 hours Medium: 50°C, usage time: 6 hours Low: 40°C, usage time: 9 hours Size: Large: suitable for shoe size 41–46 Small: suitable for shoe size 35–40