BTW, is not a Battery Case for Z1, it's a Portable Battery to charge your portable devices. It looks good but the job it do like many others. I hope they take care of the efficiency like of the looks.
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My Evolution: Sony Xperia Z1, HTC HD2, HTC Diamond 2, HTC HD Blackstone, Nokia 7070 Prism, Qtek 9100, Nokia 3100, Motorola T720i, Nokia 3310, Sony Ericson PF 768 (Blue)