question regarding rear projection mirror

[MrGizmos]

I have a mirror from a rear projection TV that has never been used. The
question is: Is there anything special about these mirrors? It is not a
first side mirror. I'm a bit hesitant to relegate it to the trash heap.
Regards, Sal

 

[BWL]

Well, they're optically flat, which is a big step up from what is normally used
in home mirrors.