4U 20槽容錯式工業控制計算機 Main Features 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 drives， and one internal 3.5" HDD Three 12 cm / 114 CFM ball-bearing cooling fans Front LEDs and audible alarm notifications for system power status， fan operation， HDD status， and in-chassis temperature monitoring Dual top cover designed for easy maintenance Five easily replaceable air filters provide good airflow Redundant power supplies are all with dual AC inputs