The ActionHeat battery heated insoles are the perfect option for anyone with cold feet! Whether you are hiking your favorite trail in the Poconos, or deer hunting in Iowa, you will love the warmth and comfort of the ActionHeat insoles. With built-in, ultra-fine heating panels strategically placed under the toes, they are the best heated insole option on the market. The easy-to-use controller has 3 heat settings and the insoles can last up to 8+ hours while reaching up to 140F with a push of a button.HOW TO USE: Charge Up – Fully charge insoles with provided charger cable (the battery is built into the insole) Insert - Place insoles in shoes or boots Turn On – Choose desired heat setting by pressing "I" "II" or "III" on the controller or on the back of the insoles. Features: Heats up to 140F for up to 8+ hours Easy to use wireless remote control with 3 heat settings An integrated heating system with built-in 3.7V rechargeable batteries Ultra-thin and lightweight design for maximum comfort Fits in all types of footwear, shoes, and boots Heating System: 3.7 Volt Sizes Available: S/M, L/XL Material Contents:Fabric: Deodorized breathable fleece lined soft shellEstimated Heating Times: High (III): 140F – 3+ Hours Medium (II): 120F - 5+ Hours Low (I): 100F – 8+ Hours ActionHeat Insole Sizing: Cut-to-fit adjustable sizing with an easy guide. S/M: Men's 4-9, Women's 5.5-10 L/XL: Men's 9.5+, Women's 10.5+ Includes: (2) ActionHeat Rechargeable 3.7V Insoles W/ Heated Toes (1) Dual micro-USB charging cable