I have a 2264.50.00 Seamaster 300 quartz (c.2009) and I want to get a case back o-ring before I open it up to change batteries. One would think this would be easy to find, but it appears that I need to know the diameter of the o-ring (and, I suppose, whether it's a round or square cross section) to order one.

Anyone know? Thanx.

 

Archer 'll be the best qualified to answer your question.

 

The part number you need is 088NS5143.

Cheers, Al