This is listed as a 52x24x52x16 combo drive, yet says:

"8X DVD+R Disc Writing Speed / 4X DVD+RW Disc Writing Speed"
"6 GB free space for DVD authoring "
"The DBW-521 has 16X speed DVD-ROM disc reading, 52X speed CD-R disc writing, 24X speed CD-RW disc writing and 52X speed CD-ROM disc reading capabilities."

http://www.imixnetwork.com/nute52xcd16c.html