Reproduction WW 1 US Army Enlisted Man's (EM) Collar Disc, Aviation.  
Stamped bronze colored metal with screw back attachment. 
Size is 1 1/16 inches round, post is 3/8 inches long. 
Listing is for 1 disc, Wing with Silver Prop.
Stock photos.
Thanks for shopping NCHSinc.
Store use only
Inside Rack 30, Shelf A, Drawer 13