SIIG's 4-port Industrial USB to 422/485 Serial Adapter with 3KV Isolation is a high quality industrial USB plug-and-play adapter designed to add four RS-422/485 ports to desktop or notebook computers. This industrial USB to serial adapter supports serial port data transfer rates up to 230 Kb/s. It features built-in 4KB FIFO buffer, auto data flow control, 15KV DC ESD serial interface protection, and 3KV optical isolation to protect the unit from ground loop noise and unforeseen power surges.