Easy to Use - Press the button for 2 seconds to turn on/off the warmer. Click to switch the temperature level. The grade 1 temperature is 104F , grade 2 is 122F, grade 3 is 140F. It takes 2.5 hours for a full charge. 3 levels temperature - Constant 104F/122F/140F, 3 levels of temperature heating warms your both hands, fast heating up in seconds and instantly release the warmth for you. hand warmer can More than 4-8 hours. Safety Quality Upgraded - Made of high-tech aircraft-grade aluminum and ABS material, handy and easy to carry anywhere. Anti-skid surface treatment makes the touch more comfortable, Smooth and warm, portable and compact. The cartoon appearance is super cute. The optimized circuit extends the lifetime of our hand warmer and provide protection against over discharging, over charging, overheat, and short circuit. Wide Use - This rechargeable hand warmer can be used for hand warming during outdoor sports, camping, skiing, hiking, and work in winter. Its MUST have a hand warmer to spend cold winter, especially for Raynauds arthritis sufferers for heat therapy needs. This device keeps your hands warm on cold days. Perfect gift for family and friends in winter