Optional thermal insulation for building a smart fireplace into any through niche of non-flame-resistant materials.
It is installed into the niche after the installation of drywall (or other wall material). It has two cover frames.
You can safely build a stone into a through niche with plasterboard, chipboard, wood and other non-flame-resistant materials.
The peculiarity of this case is that it allows you to install the fireplace so that it can be seen from two sides, from two adjacent rooms.