The optional Exotek 30mm Aluminum Fan Blaster Shroud is designed to blow your fans air directly onto your motor for maximum cooling effect while also acting as a finned heat sink for additional heat dissipation. This cleverly designed shroud positions the fan about 12mm away from the motor can to help prevent the motor magnets from impeding the fan motor. Use the supplied M2.5x16 screws to attach your 30mm fan to the shroud and then attach the shroud to Exotek Fan Mount (EXO1718 - sold separately).