Interesting square / level

[Hemlock]

My father picked up this level yesterday. There is a square extension which is attached with a thumb screw. It can be set to 90 or 45 degrees. The extension isn't held very precisely by the pins. Do any of you know anything about it, or the company?

 

[skruft]

I have one. I believe the extension can be fixed firmly but at only a 90 degree angle.

 

[turbowoodworker]

I can't tell from the pictures but is it not just a fancy bevel gauge?