DUAL USB PORTS - Delivering up to 2.4 amps, the PR-71S not only protects your sensitive electronics from AC surges but also offers the convenience of USB charging. Simply connect your USB devices to the USB ports on the front of the PR-71S. LED INDICATORS - The status indicators on the PR- 71S let you know when your connected equipment is protected, if the AC outlet the PR-71S is connected to is properly grounded, the correct polarity, and if unsafe voltage is coming from the wall. PROTEK SERIES - The ProteK series of surge protectors from ELAC provides sophisticated protection for your sensitive electronics.