Glossary
A caseback made of sapphire crystal instead of solid metal, letting the movement be viewed without opening the case.
An exhibition caseback makes it possible to check a movement's finishing, engravings, and caliber markings without disassembly, which speeds up visual authentication considerably. It also makes it easier to spot a movement that doesn't match the reference, such as a generic outsourced caliber installed where an in-house movement is expected.
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