Never be caught powerless again! Discover the Rolling Square TAU 2, a pocket-size dynamo that changes the game for on-the-go charging. Recharge on the move with the Rolling Square TAU 2. This mini power bank is a 2,000 mAh battery on a keyring. With NFC integration, it’s everything a busy professional, student, or parent needs. As an editor and mom who frequently works from coffee shops and bookstores, my devices must…