It depends on the model. The difference is essentially in the inclusion or exclusion if crown guards. "Straight lug" speedmasters don't include crown guards, and therefore the case is measured by it's diameter, excluding the crown and pushers as seen below:
View attachment 551222
Compared to "twisted lug" speedmasters, where the update to the case bumps up the previous measurement by a few millimeters:
View attachment 551221
Otherwise, the diameter of the dial and bezel are
generally the same across moonwatch models.
Click to expand...