Dynatron Cooling Fan/Heatsink A6 Material Copper Base & Aluminum Stacked Fins with Heatpipes embedded Fan Dimension 77 x 77 x 20 mm Bearing 2 Ball Bearing Noise Level At Duty Cycle 0~20%: 20.6 dBA, At Duty Cycle 50%: 35.1 dBA, At Duty Cycle 100%: 51.4 dBA