TrolMaster Carbon X CO2 Alarm StationThe AS 1 CO2 Alarm Station Set consists of the DSD 1 Dry contact station and the AS 5 audible visual alarm. The AS 1 alarm set can be mounted inside or outside grow rooms or grow facilities. It will sound both audible and visible alarms in the event where CO2 level goes above normal or safe levels. When paired with the CBA 1, the AS 5 can be linked to either AL 1 or AL 2 CO2 sensors channel, or it can be linked to both sensors for complete redundancy.