Hello,
This piece is 1 inch wide by less than a sixteenth of a inch thick looks copper to me with a slight patena of green, A little larger than a quarter by maybe a sixteenth, seems to be flat on the bottom with a very slight rise on front. TIA Steve
I think you are correct, the cross hatching pattern looks to fine to be the Type II, which leaves Type I, which was used from 1910 - 1924. Good link for dating US Army Collar Discs or Collar Brass.