External Dvd-Rw Drive (On Selected Models) - Asus UX51VZ E-Manual

External DVD-RW drive (on selected models)

The bundled external optical disc drive supports disc formats such
as DVDs and CDs. It also allows you to write and rewrite data to these
disc formats.
To connect the external DVD-RW drive to your Notebook PC:
A. Connect the two USB Y-cable connectors to your Notebook PC.
B. Connect the mini USB connector to the mini USB port on the
ASUS DVD-RW drive.

USB 3.0 ports
Notebook PC E-Manual