After i put up the Motorvoltage on the Driverboard to get more power.. and stop clocking.. the Motor gets a little to Hot inmy feelings so i invented these cooling Stuck-on... nothing to screw on.. just put it in the place.. you need a Cooling Fan same size as the Nozel! Good thing is it also cools the Board... it took a low DB Fan.. if you don´t care and take a powerfull Fan you will cool the Mainboard perfect!