Extract Rate: Impressive 26 litres per second, 96 cubic metres per hour. This is one of the highest extraction rates for any 4" axial fan.Sound output: 26.5 dB (A) @ 3 metres. This is one of the quietest fans in the market. Awarded Quiet Mark award 2013.Sound output: 26.5 dB (A) @ 3 metres. Power Co..