Difference between ASUS CD-S520-A5 and CD-S520/A4/AS QT/52X?

vbimport

#1

I am wondering what the differnces are between these two ASUS CD-ROM drives:

CD-S520-A5
CD-S520/A4/AS QT/52X

I’ve looked at ASUS’ site and can’t see any glaring differences. The last one is $4 more than the other at Newegg. Their site also does not reveal any glaring differences between them.

Thanks!
Bob