Foxnovo Durable Aluminum Alloy Heatsink Heat Sink with 5V Cooling Fan for 110 Car 540 550 3650 Size Motor

hello which test metal should seek 5 volts cooling fan for 1 to 10 scale car for example it can be 540 class motor for quick tests I will use my own connector this connector career from Futaba to jst for test I will use five volts you back from Bangor and to earth where 37.4 volts you can hear that the cooling fan started to walk airflow is good after that I will use it with mine 540 plus mortar only one thing to say if you modern in either where is draw magnetic field it can be problem for the coolant man to start you can check this if you play any metal thing on your motor if magnetic field is strong you will think a little thank you