HOW TO USE: Power Up - Charge the provided ActionHeat 5-Volt batteries. Plug-In - Connect the batteries to the USB cords located in the pocket on the side of the slipper. Turn On - Press and hold the touch-button control on the sock for 3 seconds. Press the button to cycle through the heat settings. DESIGN: Heats up to 130degF Heating lasts for hours Wool blend and fuzzy lining for warmth and comfort Powered by rechargeable 5V batteries and can last up to 5 hours Three heat level settings Turn off LED ghost-mode Weather resistant