The SDOCK2U33RE Dual 2. 5/3. 5" SATA HDD/SSD duplicator dock lets you duplicate/clone an existing hard drive without the use of a host computer system -- or dock and swap drives from your desktop or laptop computer simultaneously, using a single USB or eSATA port. The SDOCK2U33RE offers convenient dual-function performance. As a hard drive duplicator, the SDOCK2U33RE lets you create an exact sector-by-sector clone from one hard drive to another, including partitions and boot sector information -- ensuring data integrity and consistency for sensitive operations, such as data recovery. As an external hard drive dock the SDOCK2U33RE lets you connect your drives through either eSATA or USB, with each drive slot individually supporting high capacity 2. 5/3. 5" hard drives or solid state drives, tested up to 4 TB. With support for SATA III (6 Gbps) you can maximize efficiency with duplication speeds up to 22 GB per minute, and eSATA docking speeds up to 6 Gbps. The Dock can also be connected through USB 3. 0 with UASP for transfer speeds up 5 Gbps (70% faster than conventional USB 3. 0). See our UASP testing results below for further details. Standalone sector-by-sector hard drive duplication with speeds up to 22GB per minute. Supports both 2. 5" and 3. 5" form factor hard drives (HDD) and solid state drives (SSD). eSATA and USB 3. 0 host interface connections. 1:1 hard drive duplicator and docking station. Support SATA III (6 Gbps) and UASP for optimal performance. Supports dual drive capacity up to 4 TB per slot (8 TB in total). Compatible with SATA revision I/II/III (1. 5/3. 0/6. 0 Gbps) drives. Compatible with USB 3. 0/2. 0/1. 1 (5 Gbps / 480 Mbps / 1. 5 Mbps). Dual bay, top slot-loading design with drive doors. OS Compatibility: OS independent; No software or drivers required. What's in the Box: SATA HDD duplicator dock, USB 3. 0 cable, eSATA cable, universal power adapter (NA,UK,EU, ANZ), instruction manual. Clone a 2. 5in/3. 5in SATA drive without a host computer connection, or dock the drives over USB 3. 0 or eSATA for easy access.