I received Biontek's Ultra Slim Mobile Phone Power Bank Charger , in exchange for honest review from Tomoson. I wanted to review the power bank to help charge my multiple devices, more so my Kindle and Phone.
The power bank has a built-in LED battery meter. When it is fully charged, you will see four lights and when it is going dead, you will see one light. The power bank was easy to charge. I had no issues with this product.
You can purchase the power bank, using the link above. The power bank is prime-eligible.