Installs into a standard 3.5" floppy drive bay & connects to the motherboard's USB (Universal Serial Bus) connection USB 2.0 interface, backwards compatible with USB (Universal Serial Bus) 1.1 Supplied with 2 SATA HDD trays Compatible with Windows 98SE/ME/2000/XP/ Vista/7, Mac OS 9.0 & Linux This USB (Universal Serial Bus) 2.0 Data Dock is a very compact unit that means that you can add two 2.5" SATA hard drives to your desktop computer, with a simple insertion/ejection mechanism. Important Information: Hard drive not included. This product supports hard drives up to 9.5mm high only.