The Yeah Racing Aluminum 540/550 Motor Heat Sink with Twin Tornado Fans. These optional fans mount on the included bracket and use only one wire for power. This means you get two fans off one power source. The included heatsink mount has been designed to fit on both 540 and 550 motors. Available in multiple colors to ensure you can best match your ride. Package includes one motor heatsink, on fan mount, two 30mm fans and eight cap head screws.