Dual Relay CO2 Storage Safety Alarm CO2 storage safety alarm meets NBIC, IFC, NFPA inspection codes in 50 states Remotely monitor CO2 levels in CO2 storage closets, cool rooms 2 audible/visual alarms - high CO2 pre-alarm and emergency evacuation alarm Built-in relay can start exhaust fan to evacuate CO2 from area Easy to install. Provides peace of mind protection