The True Fin GLE Heatsink for the BAC 4000 is a testament to function meeting form. The only heatsink designed with deep 6mm fins to drastically reduce controller temperatures yet spaced well enough to prevent debris accumulation. The fully enclosed top bracket and integrated mounting sides are purposely designed to withstand the most brutal enduro courses. The tapered lower design serves several purposes        Easily slide off logs and large obstacles       Directs cool air into the motor cage to cool the motor       Protects your controller from harsh                                Underbelly impact and debris       The most flush mounted design in the entire market The True Fin GLE Heatsink comes with all needed accessories to mount any GLE BAC4000 controller and works on any and all BAC4000 controllers including those not purchased at Green Line Engineering.   Install video link   https://youtu.be/eG6z1tCsuZY