Wall Mount Carbon Monoxide Transmitter in house air clean ... protection connector,high reliability and anti-interference ability optional 2 relay outputs: warn & switch control Range 0-400ppm ... COutput: 4~20mA, 0~10VDC, RS485/ModbusRelay output: 2×SPST, 1A/30VDC, 0.5A/125VACResponse time:<=60sPower supply: ... value: relay action, 9ppm - # 1-6 PPM/OFF, 2 #, ON/OFF 20ppm - 25ppm - and also can be customized ...