Feature: RECHARGEABLE BATTERIES HEATED SOCKS Rechargeable heated socks are equipped with 2pcs 2200mAh/4000mAh Large Capacity Battery, providing you with up to 10-20 hours enduring warmth. 3 HEATING LEVELS Heated socks have a 3 heat settings that adjusts the temperature you like.High heat(65), medium heat(55), and low heat(45) make this electric heated socks ideal for keeping your feet warm in the winter. ONE SIZE FITS ALL Heated socks for both men and women, long cotton socks can cover the calves, warm and comfortable!Electric socks are ideal for indoor/outdoor winter activities such as fishing, camping, snowboarding, hunting, hiking, outdoor work, etc. SAFE AND WARM SOCKS Heating socks was made of high-quality cotton fibers, insulation provides you with safe socks, stable temperatures that stimulate blood circulation on your feet and keep your feet from being cold and stiff in the winter. PERFECT GIFT IN THE WINTER & PACKAGE Electric socks are the perfect gift for parents and friends at Christmas, Halloween, Thanksgiving, Birthday and other festivals. --2200mAh Battery Use Time&Temperature Indication:Low heat(45),Can be used for up to 10 Hour.Medium heat(55),Can be used for up to 7 Hour.High heat(65), Can be used for up to 5 Hour.--4000mAh Battery Use Time&Temperature Indication:Low heat(45),Can be used for up to 20 Hour.Medium heat(55),Can be used for up to 16 Hour.High heat(65), Can be used for up to 11 Hour.Battery Charging Time:About 4 Hours --How To Use:Power Up Charge the provided 3.7V batteriesPlug-In Connect the batteries to the cords located in the pocket on the top of the sockTurn On Press and hold the power button on the battery for 2 seconds --Washing instructions:1.Be sure to remove the battery before washing,and insert the battery cable into the battery pocket(note that the battery can not be washed) --Battery maintenance:1.The battery should not be close to the source of supp;y or close to high temperature objects.It should not be soaked,not dropped,and should not be disassembled.2.The battery should be stored in a dry and cool place.