Oil Cooler System

oil cooler
This looks like a small Radiator used to cool off the engine oil or the Automatic transmission fluid. As air passes through the cooler, the temperature of the oil in the cooler is reduced. Some units reduce the temperature of the manual Gearbox and Differential lubricants in racing cars.
A heat exchanger for cooling oil. Most automatic transmissions are equipped with an oil cooler that's located inside the radiator. Since the radiator usually runs close to 200 degrees, the amount of "cooling" this kind of setup provides is questionable.

system
A set of organs in the body with a common structure or function
A set of connected things or parts forming a complex whole, in particular
instrumentality that combines interrelated interacting artifacts designed to work as a coherent entity; "he bought a new stereo system"; "the system consists of a motor and a small computer"
(physical chemistry) a sample of matter in which substances in different phases are in equilibrium; "in a static system oil cannot be replaced by water on a surface"; "a system generating hydrogen peroxide"
a group of independent but interrelated elements comprising a unified whole; "a vast system of production and distribution and consumption keep the country going"
A set of things working together as parts of a mechanism or an interconnecting network