High Quality: With high quality materials and superb technology, the heater is durable and can be used for a long time. Easy to use: The heat sink cooling fan can be powered by the receiver, which is convenient and easy to use. Good heat dissipation: This radiator has a perfect heat dissipation effect, which can effectively prevent the motor from overheating and ensure the normal operation of the motor. Good performance: This heat sink is equipped with a 4.8-6V cooling fan, which can more effectively protect the motor of the remote control model car. Applicable to: The heat sink is suitable for the 540/550/3650 motor of the remote control car model. It is perfectly compatible and is a very practical accessory. Applicable motor: brushed 540/550 brushless 3650/3660/3674 (motors with an outer diameter of 36 mm can be used )/ Fan: 4cm x 4cm x 1cm super large fan, and it is a ball fan, with super large heat dissipation, and its service life is more than 3 times that of conventional ordinary fans. Product weight: 50g material: metal Colour: silver Number of pieces delivered: 1 piece