Whether you're on a plane or trekking in the woods, Eton's BoostBloc 4000 provides the power you need to stay fully charged wherever you are. It's a super-smart backup battery pack with 4000mAh lithium battery. Just give the BoostBloc 4000 a shake and the LED charge indicators will let you know how much battery charge you have left. The BoostBloc 4000 features a Micro-USB DC input to use with most smartphone chargers and a standard USB port for charging any mobile device. So small and lightweight you can take it anywhere. Stash it in your pocket, purse or pack for an anytime power boost. When the BoostBloc 4000 is all charged up, you'll have enough backup power to recharge your smartphone up to two times.

• USB output: 5V=1A
• Backup battery pack with rechargeable 4000mAh lithium ion polymer battery
• Fully charges most smartphones two times when fully charged
• USB output to charge smartphone
• LED battery charge indicator
• Shake unit to check battery level
• Micro-USB DC input for use with smart phone chargers (iPhone block, etc)
• Included: Micro USB cable
• Size: 1" x 2.2" x 2.2"
• Weight: 3.7oz