DS-24D External 4U 24 Bay Hot-Swap SAS/SATA Rackmount JBOD Enclosure 24x hot-swappable SATA II, III/SAS 6G drive bays 6x SFF-8088 external connectors, each SFF-8088 port support 4 SAS or SATA drives; LED indicators for power and activity on each HDD tray Backplanes are horizontal mounted for better ventilation RoHS Compliant, OS Independent, Come with full range power supply