I know there has been discussions about how long a 992B will run on a complete wind. I have always said over 50 hours. Well I decided to check an early model that I have on right now. I wound it at 11:30 AM Thursday. Here it is 6:30 PM Saturday and it is still running! 55 HOURS!!

The first full two days it was 3 seconds fast. It is losing a little time now, but still running.

Regards,
Larry

Larry,

Here is the Hamilton factory Dynavar mainspring which delivers those amazing run times for the 992B, 950B and 4992B's.

Rob
www.pocketwatchrepairs.net

That's neat Rob. I can't remember who I got mine from here, but they came in a little different packaging. I bought so many that one bunch was stapled to a 3X5 card.

This one stopped at 57 hours 14 minutes, and 50 seconds running time.

Regards,
Larry