This B&H Kit includes Synology DiskStation DX213 2-Bay Expansion Unit and 2 x 2TB Western Digital Hard Disk Drives, providing you 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 selected Synology DiskStation models. It seamlessly scales up the storage capacity of the DiskStation by adding 2 hard drives on the fly when connected directly to an expansion cable.You can create a connection with the Synology DiskStation using an expansion cable with custom-designed connectors on both ends, ensuring a reliable connection and maximum throughput. The 3.0 Gb/s connection speed allows the hard drives connected in it to operate as the internal ones of Synology DiskStation. The Western Digital Hard Disk Drive features a SATA 6 Gb/s interface along with a large 2TB storage capacity, giving you fast access to a large amount of data. This drive is designed for optimal performance in 24/7 NAS environments. Along with enhanced NAS performance, you also benefit from enhanced energy efficiency greatly, reducing the cost involved in running a variety of NAS solutions.