ARCTIC F9 PWM Rev. 2 is a 92mm PWM-controlled case cooling fan with ultra quiet blades delivering the most efficient combination of optimum air flow and low fan noise. Fluid dynamic bearing offers extended service life and lower noise operation over ordinary case fans with conventional bearing. At only 0.4 Sone at full load, ARCTIC F9 PWM Rev. 2 is one of the quietest case fan on the market today. Two-way push or draw mounting options provide the most flexible applications. Comes with a 6-year limited warranty.