StarTech PEX4S553B 4-Port RS232 PCI Express Serial Card - Wired - 250 Kbps. (Refurbished)The PEX4S553B 4-Port PCI Express Serial Card (with breakout cable) lets you add 4 RS232 serial ports using a single PCIe expansion slot. The PCIe Serial Card includes a 1-to-4 break out cable, which enables you to add 4 serial ports to a single low profile slot. The serial adapter card features a native single-chip design that provides optimum reliability and speed, reducing the CPU load by up to 48% over conventional bridge-chip serial cards - a cost-effective solution for connecting legacy serial devices to PCIe-enabled computers. The multi-port serial adapter includes both full profile/height and low profile/half-height brackets for compatibility with standard and small form factor computers, and is compatible with a broad range of operating systems, including Windows 7/Server 2008 R2, 2003/Vista/XP (32 and 64 bit), Linux Kernel 2.6.11 and up, as well as MAC OS 10.5 and above. This product is a replacement for the PEX4S552B card.This is a refurbished item restored to meet manufacturer quality standards. They may show limited signs of use and cosmetic blemishes and carry a manufacturer warranty. If the manufacturer is unable to assist with the warranty, Tech For Less will warrant the item with the same coverage as the manufacturer. These items can be in the original manufacturer box or repackaged for protection during shipping.Model number: PEX4S553BProduct Name: StarTech PEX4S553B Serial AdapterDevice Type: Serial adapterForm Factor: Plug-in cardInterface (Bus) Type: PCI ExpressConnectivity Technology: WiredData Link Protocol: RS-232Data Transfer Rate: 250 KbpsProcessor: MCS9901Interfaces: 4 x serial - RS-232 - 9 pin D-Sub (DB-9)Compatible Slots: 1 x PCI ExpressDimensions: 0.8 x 2.4 x 2.8 inchesWeight: 8.0 oz