External Connectors: 2 x eSATA Operating Systems Supported: PC: Windows 2000/XP (32-/64-bit)/Server 2003 (32-/64-bit)/Vista (32-/64-bit) Mac: OS X v10.4.x or later Features: Easily adds 2 external (eSATA) ports to your PCIe equipped desktop PCI Express 1-lane (x1) SATA II adapter works with PCI Express slots with different lane width RoHS compliant Installs in any available PCI Express slot Featuring the latest eSATA (external SATA) connectors to provide the most convenient way to add high speed, high capacity hard disk drives Supports hard disk hot-plugging Parts: 1 year limited