1x serial RS232 port with MCS9901 chipset. Complies with PCI-Express Specification Rev 1.0a with data transfer rate up to 2.5Gbps. Complies to Expresscard/34 standard running on PCI-e interface.Supports Plug & Play and Hot Plug feature. Supports Windows 2000, XP 32/64-bit, Server 2003 32/64-bit, Vista 32/64-bit, Linux, Mac OS, and DOS