These sophisticated steampunk beauties feature vintage watch movements (a.k.a. watch inner workings.) They would commonly say “17 jewels” or “some number” of jewels on the actual watch face, referring to the rubies. Why would someone waste rubies inside a watch?  They are used as bearings for moving parts due to their low friction and good wear characteristics. Low friction equates to increased accuracy in watch movements, so better watches use jewel bearings, even to this day.  Due to the nature of antiques, movements will vary, however quality and beauty will not.  Overall length 1-3/4″ including ear wire.  Movements vary in size, but average 3/4″ x 5/8″.