|It is not just a case. It is a User Friendly case.
Metal Fan Bracket can hold a 8 cm fan. It can be installed on the 3 1/2" hanging drives area to replace the 3 1/2" hanging drive bracket. You can adjust the fan direction to blow air to hot spot (most likely CPU, high end graphic card, or memory). This is most useful when you have a dual CPU high end system.
Picture of the metal fan bracket
Engineering drawing of the metal fan bracket