This IO Crest SI-PEX15043 2-port RS232 Serial PCI-Express Card, DB9 Female Panel Mountable Field Terminator Adapters, Ear Chipset XR17V358 series Multi-I/O PCI-E controller cards are high performance RS-232 serial interface controllers for home and industrial users. They are compatible with industrial standard 16C550 UART, which conveniently provide a low cost connection platform for industrial machines, POS machines, external modems, mice, and etc.