1.USB recharageable hand warmer
2.best product in cooling winter
3.USB charge.plam and portable
4.built-in recharge batter

1. Environmental-friendly.plam and portable
2. operation time:6-7hours(low),3-4 hours(high)
3. surface temperature:39-48C   charging time:3-5 hours
4. charging by USB port or USB adaptor(DC 5V,1A)
5. Built-in rechargeable LI-ion battery

6. Hand warmer is best product used in winter.