Introducing the Spectre PWM Fan Series from BitFenix. Engineered for both silent operation and maximum airflow, Spectre PWM will keep your CPU running cool without sounding line an airplane hangar. Sickle fan blades enhance airflow without producing excess noise, and two available colors match just about every chassis on the market.PWM TechnologySpectre PWM uses pulse width modulation technology to adjust fan speeds. This technology enables your system to control your cooling with much greater precision than conventional linear voltage fans, making them perfect for CPU coolers. Silent OperationKeeping your cool shouldn\'t mean having to make a racket at the same time. Spectre PWM fans are designed to cool silently, so you can keep you mind focused on the task at hand.Enhanced AirflowSpectre PWM fans feature sickle fan blades, which create a torrent of air without creating excess noise. This means that your system stays cool in the heat of battle without disturbing your computing environment. Aggressive Looks Both On and OffSpectre PWM fans are made out of thermoplastic crystalline polymer, which lends a luxurious matte finish for a classic look. Specification- Dimensions (mm): 120 x 120 x 25- Current (A): 22.5 dB(A)- Speed (RPM): 700-1800 RPM 10%- Air Flow (CFM): 51.3 CFM- Noise (dB-A): 22.5 dB(A)- Air Pressure (mmH2O): 1.88 mmH2O