Welcome to the store! 1. 2 SERIAL PORTS: The PCIE RS232 allows users to add two serial RS232 BD9 ports to desktop computers or industrial equipment via the PCI Express slot on the motherboard. 2. PCIE X1 INTERFACE: The full-height bracket of this expansion card is suitable for standard-sized PC computers, based on the PCIE X1 interface, and can operate in X1, X4, X8, and X16 slots. 3. OPERATING SYSTEM SUPPORT: Requires driver installation for Windows XP, Vista, 7, 8.x, 10, 11 (32/64 bit) systems. For Linux kernel 2.6.x, 3.x, 4.x, 5.x, refer to the compiled source code. 4. SUPPORTS 256 BYTE DEPTH: The PCIe serial expansion card utilizes the ASIX AX99100 program, supporting on-chip 256-byte deep FIFO transfers. Suitable for Intel and ARM hardware platforms. 5. APPLICATIONS: The PCIE serial DB9 port card seamlessly connects POS systems, industrial measurement and control devices, security systems, logistics management devices, scanners, printers, and other serial DB9 port devices. Item Type: 2-Port PCI Express RS 232 DB9 Serial Port Card Material: PCB Chip: For ASIX AX99100 Bus Interface: PCIE X1 (compatible with X1, X4, X8, X16) Expansion Interface: 2xRS 232 1 x 2-Port PCI Express RS 232 DB9 Serial Port Card Your satisfaction is our top priority. We will provide you with the best service. If you encounter any problems after receiving the product, such as damage or incorrect quantity, please contact us immediately, and we will provide you with the best solution!