Mainspring Service Replacement Swiss Part For EXCELSIOR PARK Watches Cal. 4, 20, 40, 42, 3364, etc. – Brand New & Sealed

Brand new and sealed mainsprings for EXCELSIOR PARK movement calibers 4, 20, 40, 42, 3364 and more. If you are having your watch serviced, do yourself a favour and change the mainspring as part of the service; the mainspring is one of the most important parts in a mechanical movement. If your watch does not yet need a service, keep one for future use, as these are getting harder and harder to find. You WILL need it at some point and it will greatly extend the life of your watch and also its accuracy. Please note that I do not accept returns for such parts. Feel free to contact me for whatever questions you might have.