[iso1631]

The inner pane (isn't it plastic?) is far easier to replace when some annoying kid devices to scratch their tag into it with a nail file.

[traceroute66]

> The inner pane (isn't it plastic?) is far easier to replace

That's the scratch pane you are referring to.

Yes, it is made of cheap plastic and serves no structural or other purpose other than to protect the real stuff from annoying kids. ;)