Carbon Dioxide (Co2) Fire Extinguishing Systems are the most cost effective choice. Some of the features that make our Co2 fire extinguishing systems or Co2 gas flooding system appealing are that they are: PA system is of course designed by many different companies. Some are well known and popular, while some are perhaps best forgotten. When choosing your system, choose components that are proven to be reliable. You can choose the individual components separately from different manufacturers.