Star Tech. com 8-Port Industrial USB to RS-232/422/485 Serial Adapter Add eight ports supporting three serial protocols, to easily connect serial devices to your computer through USB, with 15k V ESD protection Features Converts a single USB port into eight RS232/RS422/RS485 serial ports over USB 2. 0 with four modes: RS232, RS422, 4-wire and 2-wire RS485 15 kV ESD protection (Level 4) against noise emissions and electrical voltage surges DIN rail and wall mountable