Army Corp of Engineers Mystery Piece

[bdxample]

Got these items , a bag of hearing aids, old HP calculator, and a bunch of magnifying glasses (always losing mine).
Was an estate sale, lady told me all the "good" stuff was off for consignment.

anyway, does anyone know what the purpose of the Army corps of Engineers piece might be used for?

 

[diggummup]

What's written on the back of it?

 

[bdxample]

What's written on the back of it?

Copyright symbol followed by Freeman 9995

 

[bdxample]

Is there any easy way to move this to the "what is it?" forum?