Bring your battery bank and nano to any Halo shop and choose one that fits. I cut out holes at the sides for the antenna and at the bottom for the extra wifi adapter.
Made my own tactical case for the Nano from local suppliers.
Belt case with carabiner - US$12
10,000mah battery bank (3 usb ports) - US$18
180 degree USB adapter - US$7
RaLink RT5370 mini WiFi adapter - US$12
Total came up to about US$49
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