PRODUCT FEATURES: Chassis U-Seam construction for secure EMI shielding 92mm rear exhaust fan pre-installed as standard All drive bays has full usage and no interference 4 x internal 3.5" HDD drive cage cooled by (optional) 80mm front fan 2x high speed USB 2.0 front I/O preinstalled as standard! (1394 and Audio optional) Security pad-lock loop at rear of chassis