Two 5.25" and two internal 3.5" HDD drive bays for CD-ROM or mobile rack, easy to install software and mirror disk (RAID1) Two USB ports on the front panel Can be vertically or horizontally mounted, easy to fit into space limited environment One 12cm ball-bearing cooling fan for better ventilation One replaceable air filter for easy cleaning Two adjustable positions for hold-down card retainers provide better protection from vibration Wall-mounting bracket equipped Both 8-slot PICMG 1.0 or 1.3 backplane applicable; easy to change different backplanes Field replaceable power supply bracket for both normal PS/2 and PS/2 redundant power supply, easy for changing defected power supply