This 2-Pack of i-POWER 3300 mAh Ultra Capacity Power Bank Backup Chargers drops from $39.99 to $18.99 with coupon code GXS-52 at Gear XS. Plus, shipping is free. The best price we could find anywhere else is $15.99, but that's for one charger! They feature compatibility with most USB devices including iPhone, Android, smartphones, and tablets, with enough power in each one to fully recharge an iPhone 5s nearly two times, for example. They come in six colors as well. There is no sales tax (except IL).