Add 1 parallel port and 2 rs 232 serial ports to your standard or low profile computer through a pci express expansion slotr r native single chip single lane pci express chipset delivers true pcie performancer standard and low profilehalf height bracket included to ensure fitment in any systemr easy to install and use with full step by step instructions saving time and hassler r the pex2s5531p 2s1p pci express card turns a pci express slot into two rs232 db9 serial ports and one parallel por