Watches
Mechanical movements that never need a battery, quartz day-dates that keep better time than watches costing ten times more, and dive cases rated well past anywhere you will take them.
Sapphire crystals, stainless bracelets that size by removing links, and case diameters that still sit under a shirt cuff. Mechanical watches gain or lose a few seconds a day by their nature - that is the movement working, not a fault.