Convert RS232 into RS485 signal, Port-powered, Support 2500V isolation, no power supply needed. 1 ... Plug and play, small volume, easy installation 2, Port-powered, high efficiency obtain electricity, can also worked on 3 ... : Relative humidity 5% to 95% Input powered: No power supply needed, powered from TXD, RTS, DTR signal in RS ... Weight: 50g RS-232/485 Converter(Industrial Port-Powered Isolation )