The ActionHeat battery heated insoles are perfect for anyone with cold feet! Whether you are hiking your favorite trail, watching a football game, or working outdoors, you will love the warmth and comfort of the ActionHeat insoles. With built-in, ultra-fine heating panels strategically placed under the toes, these are the best heated insoles 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 directly 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 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: 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