This one.

[historicallycrazy]

Cleaned it about ten years ago when I found it. I'm crazy but to me it's a Cypher. It uses a couple different point of vision and light tricks to make some things hidden or look different depending on how you hold it. The site I found it on belonged to james trenchard the dude who designed the great seal. I have found a lot of wild stuff there. Not sure if it's a clue to find treasure or a secret spy code breaker . Probably something completely common and I'm just day dreaming . What you guys think?

 

[DizzyDigger]

I think it's a cool button...

 

[Sandog]

I think you are right, about at least one of those possibilities.