US:
Diver's:
6645-20-001-9382 is for Marathon T-SAR (Quartz)
6645-21-558-0133 is for Marathon G-SAR (Auto)
Navigators:
6645-01-318-9833 is for Marathon Type I, Class 1 (i.e. old Type 3) (Quartz)
6645-00-066-4279 is for Marathon Type II, Class 4 (i.e. old Type 1) (Manual wind)
6645-01-544-9475 is for Marathon Type III, Class 1 (i.e. old Type 6) with date (Quartz)
6645-01-364-4042 is for Marathon Type III, Class 1 (i.e. old Type 6) (Quartz)