Mini RS232/RS485 passive converter. Maybe the smallest converter all around the world so far (February 2018); Especially suitable for various industrial control equipment with small installation space; RS485 port perfectly integrated with the device after mounting; Beautiful and classy appearance; No external power supply required; Provided with surge protection circuit; Baud rate: 0-230Kbps, self-adaptive: With terminal resistance setting switch and communication indicator: Maximum communication distance: 1200m; Plug-and-play without settings.