2nd purchase, no regrets. Can be found (with difficulty) less silent but the price differential is not worth the effort! The first came in addition to the original ones in a Enermax trick I mounted it works perfectly, no noise and very good heat transfer to the outside (horizontally mounted atop a tower extraction). From where the purchase of the second when I wished ventilated correctly the niche of furniture or hifi is my amp and my bluray player. Great, no noise and it stays cool !! (The fan is connected to the DC 12V output of the amp, I added a small resistance of 150 ohm to lower speed) Guido