The Mac Cooling Pad has two built-in fans that are powered directly from your notebook's USB port to provide continuous air flow under your notebook that prevents overheating for maximum performance. You can also adjust the cooling pad's width to the size of any notebook for a secure fit. It fits Macbook 13-Inch, Macbook Air 11-Inch and 13-Inch, and Macbook Pro 13-Inch, 15-Inch, and 17-Inch.