Rockwool Density...

Hi guys, I need some help with the kgx factor of rigid Rockwool slabs. I need to place an order for the right weight Rockwool for front & rear wall broadband absorbers. 70mm (or 3") deep slabs with a matching airgap etc. And should I use the same size and weight slabs for the side diffusers? And the corner traps?

Moved to Acoustics forum... Better fit I think. :)