Our Heated Insoles updated to include seamless Bluetooth connective via our MW Connect app, our Premium Heated Insoles provide lasting warmth and extra cushion to provide all-day comfort and relief. By providing a thermal barrier against cold ground, our Premium Heated Insoles heat the toes to promote circulation, decrease numbness, and provide warmth for up to 7 hours on a single charge. Fieldsheer’s Premium Heated Insoles take all-day comfort to the next level. Whether you’re in deep backcountry powder or an early morning job site, keep your feet warm and improve circulation to avoid stiffness, muscle fatigue, and soreness. Our ultra-thin design fits in a variety of footwear, from work boots to running shoes or ski and snowboard boots. Simply download the app on the App Store or Google Play Store, and you can control your heat settings to withstand even the harshest conditions for hours on end.Insole Features:Ultra-thin Heated insole for best comfortFits in a variety of shoes and footwearHeat Zone Under the Toes3 Selectable Heat Settings- High: 150°F - Up to 2+ Hours- Med: 140°F - Up to 3.5 hours- Low: 115°F - Up to 7 hoursBluetooth Control with MW Connect AppUp to 7+ Hours of Heat Per ChargeIntegrated 3.7voltIncludes:(1) Pair Premium Heated Insoles w/ Internal Battery(1) Split Micro-USB Charging Cable