4U rackmount chassis supports up to 4 multi-systems Front-accessible redundant power supply Shockproof disk drive bay design can hold up to three front-accessible 5.25¨ and one 3.5¨ disk drive Three 12 cm / 114 CFM ball-bearing cooling fans Front LEDs and audible alarm notifications for system power status, fan operation, HDD status, and i Dual top cover designed for easy maintenance Five easily replaceable air filters providing good airflow Redundant power supplies are all with dual AC inputs