Using MINI PCle bus interface design, suitable for platforms that require compact chassis space. The "smaller physical structure" design will greatly improve the space utilization rate. Applicable to all RS232 interface devices, including POS access control, automatic teller machines, embedded industrial automation equipment, financial payment ATM systems, transportation systems, factory automation and process control, remote access servers, etc. System requirements OS Linux 2.6.27, 2.6.31, 2.6.32, 3.x.x and above, computer with MINI PCI Express slot Name: mini PCIe to RS232 4 port colour:As shown Material:PCB Package Contents: 1 x Serial Port Card 2 x PCle Cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.