The Aleratec eSATA II 2 Port ExpressCard/34 Host Adapter x eSATA ports has 2 independent 3Gpbs eSATA ports and utilizes the SiliconImage Sil3132 chipset. It supports FIS-based switching with Port Multipliers, Legacy Command Queuing (LCQ), and Native Command Queuing (NCQ). It Supports SATA II specification with transfer rate up to 3Gbps. Backward compatible to SATA 1.0a specification (1.5Gbps). Hot plugging supported. Supports 32/64-bit Windows 7, Vista, XP and Server 2003, Mac OS X and Linux.