Noiseblocker is the specialist for extra quiet fans. In order to achieve this, the company relies on maximum quality with low manufacturing tolerances and high, technological know-how with German engineering. In addition, the manufacturer states that its technical specifications represent realistic values, which therefore can not be compared directly with other manufacturers. With the BlackSilentPRO series Noiseblocker now completes its portfolio with models with particularly extensive features. They were developed in collaboration with the community of the Portal Hardwareluxx and compared to the normal BlackSilent models in addition to the accessories also technically improved. Thus, the BackSilentPRO mutates into high-end fans. The shape of the frame and the fan blades they have in common with the normal BlackSilent, but are distinguished by a completely black design. By contrast, the Pro models adopt the better electronics (NB-EKA Plus) and the optimized bearings (NB-NanoSLI) from the Multiframe series. This enables an auto-restart function, a very low noise level and a very long life expectancy of 120,000 hours. It is a controllable PWM fan in a 140mm format. Its speed can be varied between 400 and 1,500 rpm, which makes a very wide bandwidth between silent and power operation possible. At the same time, the fan produces only 4.2 - 29.2dB (A) , with a maximum throughput of 71 CFM.Technical details:- Dimensions: 140 x 140 x 25 mm- Weight: 140 g- Material: Plastic- Volume: 4.2 - 29.2 dB (A)- Speed: 400 - 1,500 rpm- Airflow: 18 - 71 CFM- Starting voltage: 5V- Connection: 4-pin PWM (20 + 50 cm cable)- Life expectancy: 120,000 hours- Manufacturer\'s warranty: 6 years