Features: 1Equipped with two 4000mAh high?capacity batteries, supports USB charging, and can be used for 4?8 hours. 2The built?in heating elements design fits the feet tightly, making the socks more comfortable to wear. 3It supports 3?level temperature control, and the battery can heat the socks to 55C, suitable for winter use. 4It can be machine washed or hand washed. Remember to remove the battery before washing. 5Put charging cord back into battery pocket before washing, and use the laundry bag (included) to prevent the cord from being torn off. 6It can heat instep and soles of feet, stimulate acupuncture points of the feet, promote blood circulation in the body. Condition: 100% New Item Type: Electric Heated Socks Material: Cotton Color: Black Voltage: 5V Current: 2A Power: 10W Temperature Range: 40-55 (Low Temperature Range: 40-45, Medium Temperature Range: 45-50, High Temperature Range: 50-55) Battery: 2 x Polymer Lithium Batteries 8000mAh Weight: Approx. 366g / 12.9oz Size: Approx. 53x10cm / 20.9x3.9in Package Included: 1 Pair x Socks 2 x Battery 1 x USB Cable