USB thermal shoe insoles - Size M (EU 35–40)

No matter how warm you wear socks? Our insoles heat your feet within minutes, USB and instant operation, washable, and size M (EU 35–40) fits your shoe size. For work, travel, and outdoor.WJ014 USB Heated Insoles – size M (EU 35–40) Almost constant temperature 40°–50°C (depending on the weather) Fits size 35–40 Operates on USB 5V/2A (power bank/charger) Made of composite/carbon fibers distribute warmth evenly Washable | lightweight | unisex When are they useful? For work, errands, travel, outdoor cold weather. Why are they safe? Low voltage 5V (like a power bank) — safe for daily use. Comfortable temperature range 40°–50°C does not reach harmful levels for the skin when used properly. No flame or gas, heating via distributed carbon fibers without hot spots.