PEX2S553 Serial Adapter - Low-profile Plug-in Card - PCI Express - PC, Mac, Linux - 2 x Number of Serial Ports External 2 PORT SERIAL CARD: Serial controller card w/16550 UART based on ASIX MCS9922CV-AA, allows 2x DB9 ports w/bi-directional RS232 speeds up to 460.8Kbps per port, available 128 byte FIFO buffer | Upgraded version of our popular card PEX2S552 OPTIONAL CONFIGURABLE POWER: PCI Express RS232 Serial Adapter Card provides choice of 12v, 5v, or none through pin 9; Each of the 2 ports are individually configurable STANDARD PROFILE & LOW PROFILE BRACKET: PCIe multiport serial card comes w/ a standard bracket pre-installed & 2x low profile brackets incl for versatile install; supports Windows & Linux VERSATILE APPLICATIONS: For standard profile desktop/servers with uses in point of sale terminals, PLCs, control/automation in factories, scientific sensors, medical equipment, scanners, oscilloscope THE IT PRO’S CHOICE: Designed and built for IT Professionals, this PCIe serial adapter card is backed for life, including free lifetime 24/5 multi-lingual technical assistance