Size:140mm 1800rpm | Style:3pin case fans The 140 mm models of the Deep Silence fan series are supplied with a 7 volt adapter cable. At 12 volts the fan rotates at 1,800 revolutions per minute. The Deep Silence 140 mm generates an air flow of 98,3 CFM at a noise level of 20.8 dB(A). Using the 7 volt cable reduces the speed to approx. 1,100 rpm, which generates and air flow of 64.8 CFM at 12.3 dB(A).NOTE: We recommend that you set motherboard fan speed control to full speed or 12V when using the included 7V cable. Using the included 7V cable in conjunction with motherboard fan speed control may not provide sufficient startup voltage to the fans.