Working principle: USB to four-port RS232 DB9 serial adapter, used to connect to serial devices via USB port, such as serial modem equipped with DB9, ISDN terminal adapter, digital camera, label writer, handheld computer, barcode scanner , PDA, etc. data transfer rateConnector: with standard USB A type male to standard 9-pin DB9 -232 serial male connectorConductor and shield: Tinned copper conductor and triple shielding the best data transmission rate. Powered by the USB port, no external power adapter is required. Simple installation, plug and playCompatible : for Windows (10/8.1/8/7XP), , Linux, etc. compatibility. Supports almost all serial COM portsName: USB to RS232 adapterCable length: 1.2mInterface: USB, RS232Colour:blackMaterial:PVCSize:6 x 6 x 3CMPackage Contents:1 * usb to Rs232 adapterOnly the above package content, other products are not included.Note: Light 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.