External, USB-A
From Amazon
Lenovo 4XA0E97775 ThinkPad UltraSlim USB DVD Burner- Black (Pack of 1)
Compadvance
LENOVO 3.0
BuyKingston
Lenovo ThinkPad UltraSlim USB DVD Burner optical disc drive DVD±RW Black
Athema Services
lenovo tp ultraslim usb dvd burner **new retail** 4xa0e97775 - eet01