Mechanical consideration for building a ReSpeaker Mic Array v2.0 case

Hello,

We need to enclose the ReSpeaker Mic Array v2.0 behind into a rigid part 3D printed part.

On this case

it seems you have 4 holes of 1.5mm diameter but what about the inside? What is the distance between the microphone and the panel? Do you have pipe between the panel and the mic?

Can you explain the mechanical constraints we have to respect to ensure a good quality sound acquisition please?

Thanks

Could I get just a .step version of the case so I can measure what I need ?