- 1 x 3. 5' Fixed HDD drive bays , 1 x 2. 5' Fixed HDD drive bays - 1 x Slim CD-ROM bay - Support CEB (12' x 10.5'), ATX (12' x 9.6'), Micro ATX (9.6' x 9.6') motherboards - Screwless top cover - 3 x 40mm ball bearing fans wall for better ventilation