The 120 mm models of the Deep Silence fan series are supplied with a 7 volt adapter cable. At 12 volts this fan rotates at 1,000 revolutions per minute. The Deep Silence 120 mm generates an air flow of 55.4 CFM at a noise level of 12.8 dB(A). Using the 7 volt cable reduces the speed to approx. 700 rpm, which generates and air flow of 24.8 CFM at 8.1 dB(A)