>ESS1504C: 1.5U standard 19-inch rack case>Connect master device via eSATA or USB>eSATA port transmission speed up to 3Gbps>USB 3.0 port data transmission higher than normal>Powerful R / W performance: read >64MB/s, write >64MB/s>ESS1504C: Max support Internal 4 SATA HDD up to 24TB>Recommended with DVR, NVR connection