UR-105

Watch the satellites index and track the minute scale

Over an hour, the active satellite carries its numeral along the minute track and then swings away as the next indexes into position. Two things have to be right: the tracking must be accurate — the numeral's position against the scale must actually read the correct minute throughout its travel — and the changeover must be clean and correctly timed. A copy that reproduces the carousel's appearance without the gearing will drift against the scale, index at the wrong moment, or simply rotate at a constant rate. An hour of observation settles it completely.

The construction is exposed, so compare it directly

There is no dial hiding the mechanism: the carousel, the satellites and their gearing are the visible face of the watch. That makes a substituted movement effectively impossible to conceal, and reduces the visual check to comparing the exposed architecture against published images of the reference.

Small production makes manufacturer confirmation practical

Urwerk's output is small enough that the manufacturer knows its watches individually and can confirm a serial and its service history. As across this catalog's independent tier, this is stronger evidence than physical examination and should be sought first.