The pro models from noiseblocker are extremely quiet have an auto restart function and a very long life expectancy of 140 000 hours the shape of the frame and the fan blades are the same as the normal blacksilent but are distinguished by a completely black design the mounting system for the fan is particularly sophisticated and minimizes the transmission of vibrations a large silicone frame ensures a reduced volume even the cables for the noiseblocker are something special the sleeved 20