Designed for the outdoor enthusiast, the aluminium Celestron Elements Thermo Charge 10 is a 2-in-1 tool featuring a hand warmer & portable power bank. Water-resistant, dust-proof & crushproof, the Thermo Charge 10 features dual USB (Universal Serial Bus) ports for charging two devices (such as a smartphone & MP3 player) at once, & provides up to 12 hours of heat (up to 114°) when using it as a hand warmer.