Systemair Revolution Stratos AC FanOverview The Systemair Revolution Stratos AC Fan has set the industry standard for inline fans. It's the go to option for most growers. The unit moves huge volumes of air in silence. The carefully engineered casing reduce the noise without affecting air flow. The fans are available in 3 versions including 150 mm, 200 mm and 250 mm. This extractor fan is made to be powerful, and run quietly. The devices comprise an elegant, lightweight, and compact