Esata Pci-Express 3GBPS 2 Port (1 Int 1 Ext) Low Profile Host Card Adds 1 internal and 1 external SATA Port. Supports SATA transfer rate of 3.0Gbps. Fully compliant with Serial ATA 1.0 specifications. Hot-plug capable. Requires PCI-e slot. (Will not fit standard PCI slots). Fully RoHS compliant. Works with Mac OS X 10.4 (or higher), Windows 2000, XP (or higher).