Double fan heatsink for 540 motors! For heavy duty applications such as offroading or even high speed on-roading! Pre-soldered wires means that there's only one slot required to power the two fans. Feature: For: 540 & 550 Motor Material: Aluminum Fan : YA-0641 Dual Tornado Fan Color: Red Include: Fans (2 pcs) Heatsink (1 pc) Screws (8 pcs) Fan Mount Plate (1 pc)