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