IOGEAR External Power Supply for GUE310 Extension Cable, GUE310AC When daisy-chaining multiple GUE310 USB 3.0 extension cables, it is necessary to connect the GUE310AC Power Adapter. The GUE310AC enables up to four GUE310 USB 3.0 cables to be connected while still maintaining full-speed data and power requirements. Power Output - 5V / 1.5A