The ESS1504A  is an eSATA storage from Dahua for Smartview NVR, 4 BAYS, 16TB MAX 1.5RU. Features: 1.5U standard 19-inch rack case eSATA port transmission speed up to 3Gbp/s Powerful R / W performance: read >70MB/s, write >40MB/s Max support Internal 4 SATA HDD up to 12TB Recommended with DVR, NVR connection Specifications: Model DH-ESS1504A Specification   eSATA Interface 1 port, up to 3Gbps/s Internal HDD 4 SATA ports, up to 12TB R / W Performance Read: >70MB/s, Write: >40MB/s Connection Device DVR, NVR Environmental   Power Supply AC 100~240 V, 50/60 Hz Power Consumption <50W(with HDD) Working Environment 0 ~+40°C / 10~80%RH / 86~106kpa Dimension 1.5U, 442mm x 442mm x 89mm(W x D x H) Weight 6KG(without HDD)