Yeah. Kind of surprise me there aren't more interested. Or perhaps the technical level in this thread seems too high. But hey. As I've said from start - all contributions also non technical are very welcome so this thread can be the Great Thread of Quartz Marine Chronometers.
Well this is not to be a thread of cars so instead I figure I'll show some photos of the back side.
Quite different than the QM-10/11. Also the QM-20 is designed to be used flat on a table where as the QM-10/11 you have the choice between standing (NOT on a ship or in a secure holder) or laying down. Well it's no bigger deal making a stand for the QM-20 for home use even though not intended for vertical use
The hole with the grille is the small speaker which beeps once per second when doing a battery check. Sounds exactly like some one is having their heart monitored.
A look to the batteries. I've used some 2x AA parallel -> D size adapters. The black knob is for hand setting. Just like it's siblings.