This is the Castle Creations CC Blower V2 Fan for the Mamba Monster 2 ESC.
One Castle Creations CC Blower V2 Fan
Castle Creations Mamba Monster 2 ESC (CSE010-0108-00)
Input voltage: 4.8 - 7.4 volts
Maximum RPM: 10,000 RPM
Wire length: 10" (255mm)
Waterproof: No. Remove before exposing ESC to moisture.