Low power and quiet 12 volt fans. Total size of the fan 12 x 12 x 2.5 cm, can be used on power supply, to cool hard disk, CPU, other devices. Screws for installation are included. The frame is made of reinforced plastic with flammability safety standard UL94 V0. With 2.54mm 3-pin connector (3 wires) for speed control, tachyometer, rotation detection, thermal control. The fan also works with 2 wires, using only the red wire (positive) and the black (negative). Cable length: 20 cm. Nominal voltage: DC 12 V. Operating voltage: 6-13.8V. Current: 0.10A Maximum speed: 1700 RPM (Revolutions Per Minute - Fan Minute) Maximum air flow: 39.2 CFM (Cubic Feet for Minute - Cubic feet per minute, referring to the air that moves the fan). The foot is an English unit measuring approximately 30 cm. In short, it is the air flow generated by the fan. Multiplied by power, gives the idea of the fan energy efficiency. A ratio of over 75 indicates a good ratio, in this fan is much higher. Maximum air pressure: 2.3 mm H2O (millimeters of water, pressure unit) Noise Disturb: 27 dB(A) (Decibel) Clockwise rotation