This sale is for a lot of 50 new old stock vintage 5/16" X 3/4" X .025" thin BRASS flat washers. Actual inside diameter is 21/64" or .3281". Very old, surely USA made. Again, you are purchasing 50 washers. Please see pictures and ask questions if you have them. We describe our items as accurately as possible. We do not know everything, so look at the photos as well as reading description completely. I will ship internationally and will combine shipping on multiple purchases.