3 ft shielded serial RS-422 RS-485 to USB adapter cable supports windows OS, Mac and more; plug-and-play, No power supply neededUSB to RS485/RS422 converter easily lets you connect RS485 or RS422 device directly to your Laptop PC computer via USB portIdeal for industrial environment -provides 600w surge protection and 15KV ESD isolated protection on signal pins to protect costly and often sensitive control equipment against electrical damageWith high performance quality processor chip (FTDI-chipset FT232) and I/O auto conversion circuitry which makes RS 485 to USB convertor one of the most reliable dongle on the marketThere are no IRQ and COM port conflicts, since the port do not require any additional IRQ, DMA, memory as resources on the system; RS485 for Half duplex and RS422 for Full duplex communication