WWI U S ARMY 4th Infantry Division Doughboy Steel Shell Helmet.  It' rusty, dirty but Super Cool.  Looks like it was dug up somewhere.  Has Numbering on it, hard to make out (pictured)  like ?? 207 but something seems before those numbers.  Look at the pictures for full description. I believe this is a WW1 or WW2 .  Correct me if I'm wrong.  Any Education is Welcome.  Any questions ask  P.S.  This Diamond shape Insignia I find is the U S Army 4th Infantry Division.