Features: Material: This heated socks are made of core-spun yarn + tension frame + mink hair, and make the socks feel warm, comfortable and breathable. A certain degree of elasticity makes the socks comfortable to wear, not tight. Battery Included: The heated socks include an updated2* 4000mAh rechargeable Li-polymer battery, which can heat up to 10-20 hours under full charge. Design: The recessed heating element design makes the socks more comfortable to wear. And we expand the area of the heating element, the socks will heat instep and sole of the foot. To stimulate acupuncture points on the feet to maintain health and promote blood circulation in the body. Cleaning Care: This battery-heated socks can be machine washed and hand washed, remember to remove the battery before washing. Put the charging cable back into the battery pocket before washing and use a laundry bag to avoid the wire being pulled off when using washing machine. Package: 1 X pair of socks 2 X 2*Battery box 3V/ 4.5V