Others charge over $40 for this kind of extra juice! Big Power 4000mAh Power Bank For Phone Or Tablet.

It's Simple:  
  • You charge it up with the included cable (takes about an hour).  
  • Then you plug WHATEVER USB Cable into this thing (like your Apple lightning cable or Samsung USB-C cable or whatever!) into here when you need some extra juice and it'll charge your device.
  • Works on Phones and Tablets

For this price buy a couple! That way you'll always have some juice!!