Interior Of The Combo Drive
This photo gives a clear view of what is inside the combo drive. The hard drive itself sits at the front (looking at the closed case). You can easily see the model designation (see here for a review of the drive on its own). The electronics at the rear have their own, separate cover. All the connections are on the back.
The metal foil is for screening the electronics.
Not surprisingly, a Western Digital drive is used here - the WD2000BB. The Special Edition with its 8 MB cache (WD2000JB) would not have achieved a great deal, since the interface itself is the major performance bottleneck.