ATC LLC via Amazon offers the Lumsing 10,400mAh External Battery Pack in White, model no. LUM-008-01, for $29.99. Coupon code "LSMDS199" drops it to $19.99. Plus, Prime members receive free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, it costs $5.55.) That's $28 less than the lowest total price we could find for a comparable pack elsewhere. It features four LED indicator lights, micro USB input, and is compatible with a range of Apple and Android devices.