Shield in amplifier

[rdalem]

Does anyone know where to get these?

 

[chrisng]

It looks like a custom-made, oversized U-shaped heat sink.

 

[mamocel]

t looks like a custom-made, oversized U-shaped heat sink.

Given the thickness of the aluminum slats... It shouldn't dissipate much.
I would say more of an EMI barrier... Finely tuned.😏