Omega® Crown (Dustproof), calibres: 11.5, 13.5, steel, 5.25 mm
Omega® Steel Dustproof Crown for Omega® calibres: 11.5, 13.5, diameter 5.25 mm, tap 100. Case numbers are unknown.
* H. & W. Perrin Company Limited is independent of and not affiliated with or sponsored by Omega®. Omega® warranty does not apply to parts supplied by H. & W. Perrin Company Limited. Using generic parts may devalue your watch.