This is Novak’s 40x40x10mm Cooling Fan that provides additional airflow to R/C motors and electronics for improved performance. It is the same fan that is included in the Novak 1/8-scale Brushless Conversion Kits to cool the motor and is also the same fan that is included in Novak's HV Brushless Systems. It features a factory-installed two-pin JST plug that is easily plugged into the Novak HV-Series and Super-Duty XR ESCs.