The Alphacool ES fans have been specially developed for use in servers and workstations and, unlike usual, do not offer a 2 or 3-pin DC power connection, but a 4-pin PWM control. PWM control Instead of the usual 2 cables or the 3-pin connector Alphacool now also uses a 4-pin PWM connector for enterprise fans, which is supported by more and more server mainboards. Via the 4-pin PWM connector, the fan always receives full voltage and is controlled by pulse width modulation. This allows the fan to be controlled over a much wider speed range. A considerable amount of energy can be saved whilst controlling the fans in server racks and with 0% PWM control, the fans can even be stopped completely. Double ball bearings unlike classic plain bearing, Alphacool ES fans have a double ball bearing for increased service life under full load. Double ball bearings are generally regarded as the highest quality bearings in terms of durability and quality. This also ensures a high level of running smoothness in terms of minimal vibration. The Alphacool ES fans for servers and workstations offer an extremely high air flow and an extremely high static pressure. They are therefore ideal for use on radiators or as particularly powerful case fans. Technical data: L x W x H: 80 x 80 x 25 mm Speed: 600-6000rpm Bearing: Two ball bearing Connection: 4-Pin PWM Cable length: 30 cm Operation voltage: 7 - 14V Start voltage min.: 7V Power consumption: 0,66 - 0,85A (7,92 - 10,2W) Static pressure: 14,29 H2O Max. air flow: 130,83 m3/h Noise: 50 dB(A) MTBF: 70.000h Model: TR-13579-2P