This version is a foldable version of the Soldier Mask from Squid Game. There are two versions of the Top Mask, one with custom supports and one without custom supports.

The Bottom Mask is pretty much self supporting.

To stop the mask from sliding out there is a stopper that you can simply super glue to prevent the mask from sliding out. But You might not even need this, the mask seems to stay in place well without the stopper.