Zuosheng USB Heated Insoles Rechargeable Heating Insoles Multiple Sizes Electric Foot Warmer Mat for Camping, Fishing, Hiking Shoe Care Kit  (0 ml, Black)

Important Safety Precautions Do not apply on broken skin. Not suitable for infants, pregnant women, diabetics, people with poor circulation or sensitive skin. Do not use while asleep, avoid humid bathroom environments. Never cover the insoles with blankets or place near flammable items. 5V USB Low-Voltage Heating Safe 5V USB power supply. This heated insole has no auto shutoff. Limit each usage to 30 minutes and unplug afterward to avoid low-temperature burns. Powered by laptop, power bank and other USB adapters (power bank not included). Trimmable Size for Perfect Fit Cut freely along the marked lines to match different shoe sizes. Fits most adult footwear and makes a warm holiday gift for Christmas, Thanksgiving, birthdays and other festivals. Soft Reusable Material Constructed with elastic EVA foam and polyester fabric. Skin-friendly, breathable and flexible. The insoles are washable for repeated long-term use. Wide Application Works well in hiking boots, snow boots, sneakers, leather shoes and high heels. Great for daily wear, hiking, skiing and all outdoor cold weather activities.