Pocket watch crystal size chart
a Ligne to Metric conversion chart of the sizes.
The red numbers are the old (Ligne) size
tags on the crystal.
The black numbers are the mm conversion.
You need to measure your watch bezel in mm and compare.
the bezel of your watch for the crystal size in mm.
Then use the chart to get the crystal size you need.
46.1mm converts to crystal size 20 7/16. You can then tell me the size you need and purchase that one
if I have it in stock.