See: 6MIK

6MIK have introduced a new 40mm aluminium cooling fan. Standard replacement for 1/8th speed controller, the 40x40x10mm fan includes a black or red anodised aluminium fan mount sporting a heatsink design for cool looks and additional heat dissipation. The hi-speed fan features dual ball bearings to increase air flow to help to cooling and thus extend the lifespan of the ESC as well as an all-black high-quality silicone wires for a stealthy appearance. It should be plugged to the receiver in order to prevent ESC over-tension.