Stay warm on the trail and keep your portable electronic devices fully charged with the ThermoCharge power pack and hand warmer. ThermoCharge heats up quickly and reaches a maximum of 113 degrees Fahrenheit 45 degrees Celsius. The 4400 mAh rechargeable lithium battery provides up to an impressive 6 hours of continuous heat on a full charge. ThermoCharge delivers a full charge most smart phones, MP3 players, cameras and many other USB powered devices. Unlike single use chemical hand warmers, ThermoCharge is safe, scent free and rechargeable. Just plug it into any USB charging port. A rugged aluminum housing and protective silicone caps make ThermoCharge perfect for your next cold weather excursion.