Novak heat sink features high-efficiency ribbed cooling fins with the Velociti �V� shape, and is designed to fit the Novak #5647 25mm cooling fan. Height above motor is 18mm (0.7 inches). Includes thermal paste for maximum heat transfer, and installation instructions. Available in anodized black for maximum heat transfer (#5413), anodized purple to match the GTB heat sink (#5414), and anodized blue (#5415). Part Numbers: #5413 (black), #5414 (purple), #5415 (blue)