Description describe Precautions: Please do not charge and heat at the same time. Do not place it in humid, high temperature, prolonged exposure to sunlight, fire, etc. When the temperature is high, do not directly heat the skin for a long time to avoid burns. Keep away from children while charging. Smart Instant Heater: Hand warmers quickly heat both sides in seconds. Double-sided chip design, overcharge, overdischarge, overheat protection. 3 Temperature Mode: Skin-friendly, adjustable temperature for your choice. Anti-shock, anti-scalding, anti-skid, explosion-proof. With Micro USB charging port. become a power bank, Charge your electronic devices in an emergency. PERFECT GIFT: This is a must-have to get through the cold winter, It is especially suitable for the hyperthermia needs of patients with Raynauds arthritis. Great gift for Thanksgiving, Christmas, Birthday. Smart application: 2 in 1 function (heater, power bank), suitable for daily use in winter by the elderly, children in school or outdoor sports Material: aluminum alloy + lithium battery Battery capacity: 4000mAh Weight: 185 grams Output/Input: 5V/2A Charging time: about 3-4 hours for a full charge Press and hold the power button for 3 seconds to instantly release warmth for you. It quickly heats up both sides in seconds Package Included: 1 electric hand warmer 1 x Micro USB charging cable