The Reventa AirProTec filtration system offers a 97 percent protection against H5N1 viruses. It consists of special filters that are able to filter the H5N1 viruses, which have a size of 80 to 120 nm. According to studies performed by the University of Leipzig, AirProTec is filtering up to 95 percent of PRRS and even up to 97 percent of the H5N1 viruses. The fresh air filter system can also be integrated into existing ventilation ceilings. The system is available in different variants.