Thermaltake A1838 Silent Boost Socket 754/940 - AMD Opteron/Athlon 64 - Ball Bearing Copper Core CPU Cooling Fan The A1838 is designed for for the AMD Opteron and Athlon 64 processors. Unique fan frame design significantly reduces the noise level. Rated Voltage: 12V Noise 21 dBA Fan Dimensions: 80x80x25 mm Max Air Flow 27.5 CFM Heatsink Dimensions: 85x73x48 mm (46 fins) Air Pressure 25.97 Pa-min