The Victor 884 is a speed controller specifically engineered for robotic applications. The 40A capacity, low voltage drop, and peak surge capacity make the Victor 884 ideal for drive systems while its braking options and precise control meet the demanding needs of arms and lift systems.
A cooling fan operated by the input voltage of the speed controller insures that the Victor 884 is continously cooled.
This is what I found on the net/web. Not sure if you can use it for RC application since its designed for robotics. When used in robotics there should be in-line breakers to prevent it from overheating. From what I have read, when the esc provides current to the motor, it also provides a proportional current to the cooling fan, meaning when you run the motor at full speed, the cooling fan also run on full speed to keep it cool.