Tok Tok Designs&reg; 80 X 80 X 25mm (3.15 X 3.15 X 0.98 Inch) USB Fan USB Powered Ball Bearing Fan Size: 80 x 80 x 25mm (Height x Width x Thickness) Ball Bearings for Longer Life Fan Speed: 2500 RPM Conversion: 1 inch = 25.4mm