Sharkoon has introduced a rather simple but clever accessory that should put those unused optical drive bays to good use for some users. It's called the 5.25" Bay Extension that is simply a steel construct that allows users to place either two 2.5" drives and a single 3.5" drive or four 2.5" drives.
As it is intended that any 2.5" drive installed would be an SSD, those mounting holes do not have anti-vibration grommets; however, the 3.5" drives do. The bracket measures 116 x 146 x 37 mm and weighs roughly 150 grams.
Sharkoon's 5.25" Bay Extension will be available in black, red, blue and green, with no word on pricing or availability yet.