Heat Sink features a lightweight aluminum construction with a dual cooling fan design The heat sink is compatible with 1 8 scale motors around 40 8mm diameter and 57 9mm in length and includes two 30x30x10mm high speed fans that peak around 18 000RPM 6v The fans can be installed directly to the heatsink or you can use the included 10mm spacers between the fans and the heatsink for enhanced airflow Features . Fits 1 8 motors with 40 8mm diameter and 57 9mm length. Lightweight aluminum construction. Dual fan design. Excellent airflow. Includes two 30x30x10mm cooling fans Includes . 1 Heat Sink Big. 1 Heat Sink Small. 4 M3 x 6mm Round Head Screws. 4 M3 x 14mm Round Head Screws. 4 M3 x 25mm Round Head Screws. 4 10mm Washers. 2 30x30x10mm Turbo High Speed Fan Specifications . Color Black