This B&H Kit includes Synology DX1211 12-Bay Expansion Unit and 12 x 3TB Seagate Barracuda Internal Desktop Hard Drives which provides you the necessary storage and fast access to a large amount of data. The Expansion Unit delivers an effortless solution for volume expansion and data backup for Synology DiskStation DS2411+ / DS3612xs NAS.The unit seamlessly scales up the storage capacity of the NAS servers by adding 12 hard drives directly to servers. It securely connects to the DS2411+ / DS3612xs NAS via an Infiniband cable to carry 12 Gb/s SATA signal for maximum throughput. The unit also allows the hard drives in the connected DX1211 unit to operate as internal hard drives of the DS2411+ / DS3612xs with no lag in data retrieval. The Seagate Barracuda Internal Desktop Hard Drive is an internal drive with a 3TB storage capacity. This amount of storage provides the necessary space to store large files as well as a variety of multimedia content. The Barracuda hard drive is ideal for use in desktop or all-in-one PCs, home servers, PC-based gaming systems, desktop RAID configurations, direct attached external storage devices (DAS) and network attached storage devices (NAS).