4U(HE) 18.9” deep chassis supports 7-slot ATX MB. Drive bays (4)5¼,(2)HDD, (1)FDD* . Optional Temperature Alarm Board Features: 1. 4U 19" Rackmount Chassis 2. Supports ATX/EATX Motherboard 3. Supports (4)5¼ ,(2)HDD, (1)FDD* Drive Bays 4. (2) 2.0 USB ports on Front Panel 5. (1) 12cm and (1) 8cm ball-bearing fan with space for one additional fan 6. Fan failure & Temperature Alarm Board 7. Dual Lockable Front Doors and Replaceable Air Filters