Add four rs232 serial ports to any pc using a single pci express expansion slotr r native single chip single lane pci express offers increased performance for up to 48 less cpu loadr data transfer rates of up to 460 kbps for efficient serial device performancer pre configured for standard profile systems but includes a low profile bracket for versatilityr r the pex4s952 4 port native pci express rs232 serial adapter card with 16950 uart allows you to turn a pci express slot into 4 rs 232 db9