Possibly Military Button?

[filthyflyer39]

Here's a button that my uncle found about a week ago. We were wondering if anyone knew any information about it. It was at the same depth that we have been finding early 1900s coins or slightly earlier. If anyone has any ideas, please let us know!

 

[grasshopper]

It is called a collar disc device and is from ww1. nice find!!

 

[Steve in PA]

That is Great Seal button, introduced in 1902 and used in World Wars I & II.

 

[aa battery]

That is Great Seal button, introduced in 1902 and used in World Wars I & II.