Metal Sheet on one of the case walls

[haiwan]

I have a plastic case, I forget what brand/model. On one of the side walls, there is a metal (aluminum) sheet attached.

Does anyone know what this metal sheet is for? It seems like it would hinder heat transfer out of the case.

 

[haiwan]

It turns out its a Fong Kai FK-603.

 

[ThisIsMatt]

Interference shield.