I think it's the OEM version of the Panasonic LF-D521U. 2X DVD-R. Also supports DVD-RAM and DVD-RW.
The benefit of the LF-D521U is it comes with DVD-Movie Album 3, which is essential if you use Panasonic DVD-RAM based home theater standalone DVD recorders and want to be able to extract the video. Mind you several people have just gotten replacement software CDs from Panasonic directly, and if you don't plan on extracting video from those standalone DVD recorders, then all you need is Windows XP (for FAT32 support on DVD-RAM) and Nero (for DVD-R/W).