HIWARM Electric Heated Insoles Far Infrared 4 Constant Temperatures Rechargeable Foot Warmers for Men Women, Thermal Shoes Boots Inserts for Skiing, Hiking, Camping(M)

【Good for giving】 The HIWARM far-infrared heated insoles keep your feet warm and comfortable in cold winter. Get more vitality for some winter activities such as hunting, fishing, skiing, or hiking and the like.
【Largest heating zone】The largest heating zone (S:4*19cm; M:4*21cm; L:4*23cm) can provide the warmth from the toes to the heel.
【30 Seconds Rapid Heating】This product makes your feet feel heat within 30 seconds.
【4 Constant temperatures】The approximate temperature range is 36 ° C -55 ° C (97 ° F – 131 ° F). (depending on ambient conditions). Temperature can also be adjusted through the battery power buttons.
【Safety Protection】The heated insoles built-in temperature sensor, for you to stabilize at the set temperature when the temperature reaches the set value and will not overheat.
【Easy to use】Thickness: 6 mm. The insole can also be cut from size 35 to 46 to get the perfect fit. Washable (by hand or machine). The product is powered by rechargeable battery(7.4V2600mAh), and it has two how one can wear，easy to carry and use.
【Prevent slipping】The silicone on the back of the insole can prevent slipping, and the insole will not wrinkle throughout the exercise.
【4-10h Heating time】On account of the existence of temperature sensors, the amount of heat generated by different users will vary greatly. People with cold feet need more heat. Shoes with good thermal insulation performance waste less heat. More heat is required to be used in low temperature environment. Subsequently, different heat requirements directly have an effect on the heating time.