Sunon DC12V-8.0W ( 40x40x28mm) fan PMD1204PQBX-A(2).B2037

The Sunon 40 x 28mm Fan is a small and powerful, super high-speed fan that moves an impressive 23.5 CFM despite being small enough to fit on most chipset heatsinks. At 51.5 dBA, it isn't quiet, but that isn't surprising considering it puts out more air flow than most 80mm fans. The fan has an RPM sensor, so it can plug into standard 3 Pin motherboard headers and report back its fan speed.

Technical Specs.:

Fan Type:                                   Tubeaxial (Square) 
Fan Size:                                     40 x 40 x 28 mm
Input Voltage Typical:               12V DC
Cabling:                                      3 Wire Leads
Tach/Speed Sensor:                   Yes
Air Flow:                                     23.5 CFM                                  
Noise:                                         51.5 db A
Input Power:                               8.0w
Bearing Type:                            Ball-Bearing
Static Pressure:                         1.150 in H2O
Input Voltage Range:               10.2~13.8VDC
Fan Speed:                                13,000 RPM
Operating Temperature:          -10°C ~ 70°C
Flammability Rating:                UL 94V-0