Features: 1) Multiple IAQ monitor and controller, high performance with low price 2) Detect and control indoor VOC concentration with room temperature detection 3) IAQ alert according to two stages VOC values which preset by customers 4) Optional humidity detection 5) Optional one 0~10VDC analog sign outputs and two dry contact outputs 6) As a direct controller or a transmitter to send its output to any DDC or system of the control of ventilation equipment 7) Analog output: 0~10VDC linearized output or PID control output, programmable selection 8) Gas detected: smoke, sulfureted hydrogen, ammonia, hydrogen carbinol, ethanol, odorous gases 9) VOC sensor: gas sensors of semiconductor 10) Provide RS485 network interface