TrolMaster Carbon-X CO2 Alarm Station with LED display indicatorCarbon X CO2 Alarm Station 2AS 2 p>The AS 2 CO2 Alarm Station combines an audio visual alarm module with a color coded LED display indicator and an LCD digital ppm level reading. It is designed to be mounted outside of the space to be monitored, and will display the CO2 ppm level. The DSA 1 can be linked to either the low or the high level CO2 sensors, or it can linked to both sensors for complete redundancy. The green LED indicator shows the CO2