This Is Queens Hobbies Aluminum 540 Size (36mm Width) Motor Heat Sink With High Voltage Cooling Fan (5.5 - 8.4V) , This is a great option for keep Your Motor cool and consistency , you will be able to achieve cooler temps on your motor ,The cooling fan speed is around 8,000rpm 6V BEC , 9,500RPM 7.4V BEC , 8-9 Inch length Include Connector (JR Type connector) , Package includes an extra replacement fan.


Features: 
  • Fits 540 size or any 36mm width brushed / brushless motors
  • Heat sink made by aluminum 
  • Cooling Fan Voltage (5.5V --8.4V) , 9V Max
  • Fan Speed Around (8000RPM / 6V , 9500RPM / 7.4V) (Fan Speed Start From Low To High / Around 90 Sec)
  • Wire Length (8 -- 9 Inch) 

Thanks For Looking !