The K 125 M fan is a 5 inch hydroponic extractor fan made by industry leader Systemair - who also manufacture the grower's favourite RVK. The K fan is just as dependable as an RVK and will last you just as long, even with continuous use. The K 125 M is sealed to prevent any smells leaking from your grow room, and delivers a maximum air flow of 187 m3/h.