Used on V-22. ring antirotation, brg, prgb outside dia is 3.265 to 3.267 for a thickness of 0.155 to 0.165 then outside dia becomes 2.690 for a thickness of 0.274 to 0.276; inside dia is 2.410; item is flat on opposite side with a tab in the middle of the flat area, flat area starts 1.682 from the center of the item;