The ActionHeat battery heated socks are the perfect blend of quality and comfort. The ActionHeat socks reach a maximum temperature of 130F and can last up to 4 hours. ActionHeat battery heated apparel utilizes innovative technology designed to warm the core body temperature. These revolutionary garments feature built-in heating panels and are made with ActionFlex material that provides lightweight warmth, comfort, and versatility.ActionHeat heated garments use FAR infrared heating and ActionWave heat reflective technology to deliver hours of heat and comfort. ActionHeat allows you to stay warmer and enjoy outdoor winter activities longer than ever before. HOW TO USE: Power Up – Insert (3) AA batteries into each power pack. Plug-In – Connect the power pack to the cord located in the pocket on the top of the sock. Turn On – Press the red power button on the power pack to turn on. Features: Built-In heating panels strategically placed on the top of the toes use advanced ultra-fine fibers to provide superior heating performance Battery Voltage: 4.5 Volt Power Packs Power System: AA Batteries (not included) Colors Available: Black Recommended hand wash only. Note: Can use mesh wash bag for gentle machine wash. Heats 4+ Hours Unisex Fit Sizes Available: S/M, L/XL, XXL Estimated Heating Times:Heats up to 130F for up to 4+ hours.Material Contents:Material Content: 70% Cotton & 30% SpandexIncludes: (2) ActionHeat Cotton Blend Socks (2) AA Power Packs; Each Require (3) AA Batteries (Batteries Not Included)