Details: 
100% brand new and high quality. 
Diameter : 36mm 
This heat sink fits for 540,550 and 3650 size motor, it will come with a 5V cooling fan, to protect your motor. 
The cooling fan can power up from the receiver, using conveniently and easily. 
  
Package Includes: 
1 x Aluminum Heat sink with 5V Cooling Fan 

Note
We will use PE or bubble bag to pack it well and protect it well. Don't worry.
If the item damaged, please contact us firstly immediately before leave feedback, thanks for your understanding.
Due to hand measure, there will be errors, subject to the actual product
Due to Different Monitor, the color may have difference