Versatile CompatibilityThis 5V 3A heated vest battery pack (10000mAh) blends compact size with large capacity. It works seamlessly with most 5V heated gear (heatedvests/jackets/blankets/seat cushion/camping chair, golves) and smart phones for charging. Critical Note: No DC outputNOT compatible with 7.4V or 12V heated clothing. Plug in for Automatic Starting up Designed specifically for heated clothing use: no need to press a switchsimply connect the battery to your heated wear, and it powers on automatically. When not in use, it shuts into sleep mode to save power, solving the hassle of battery replacement while wearing.