StarTech.com 4 PT PCIE RS232 Serial Card Asix AX99100

This PCI Express RS232 serial adapter card lets you add four RS232 (DB9) serial ports to your computer through a PCI Express (PCIe) slot, as if they were native serial ports. The 4 port PCIe serial card enables you to interact with serial devices, such as card readers, printers, PIN pads, and modems, at speeds of up to 921.6Kbps. 

Maximum Compatibility 
With broad OS support, including for Windows and Linux, this multiport PCI E serial card is easy to integrate into mixed environments. The card comes pre-configured with a full-sized bracket, and includes an optional low-profile bracket, so installation is easy regardless of the case form factor. This expansion card is a direct replacement for PEX4S952.  

PEX4S953 is backed by a StarTech.com lifetime warranty and free lifetime technical support.