XO XRYG-280-3 21W 2xUSB foldable solar charger (black) XO XRYG-280-3 will provide constant access to power for your devices. It is equipped with 2 USB-A ports and features a foldable design, so it won't take up much space. It will be perfect for a camping trip or a picnic. What's more, it offers 21 watts of power, and its energy efficiency is 22%. Manufacturer XO Model XRYG-280-3 Power 21 W max. Open circuit voltage 21. 6 V Short-circuit current 4. 5 A Operating voltage 5 V max. Operating current 4. 2 A max. Energy efficiency 22% Output ports USB-A x2.