Swiss Case Knife
Superior quality for opening clip on case backs. The knife has a specific watch case opening end (short) for watch cases with a standard groove. The other end has a standard knife (long) with a sharper edge for those case backs with a thin groove. The standard knife is great for for all those other jobs... opening letters, parcels etc.
We use these knives in our shop for opening clip on case backs and the high quality of manufacture ensures they last for years.
The standard knife end of this tool can be extremely sharp when brand new so please be careful. After some use this will not be an issue unless the knife is highly sharpened.