LY11 series signal surge protection device is RS232,RS485/422,wired remote sensing,telemetering sensing,telemetering,remote control equIpment etc. There has 9pins and 25pins interface .Supply.line-line,line-ground surge protection . Easy install,no need maintenance,fast response, could fully protect the equipment.1.Accurate protection to communication line. 2.Quick response, low clamping voltage. 3.Transmission characteristic: 1Mbps. 4.Low insertion loss.