Universal Genève automatic winding with center seconds Ref. 313813, which appeared in the 1950s. It houses the Caliber 256B with 28 jewels, which beats at a frequency of 21600 vph. Measures 30.5 mm without the crown. Not sure if it’s white gold, stainless steel, or something else but it’s incredibly shiny. Beat error is a little high but amplitude and beat rate are amazing. Will only fit a wrist between 6.4-6.7 inches around the wrist. Not able to be adjusted. There is a broken link above the 11th hour marker, but does not seem to affect the wear of the watch. Just take care not to pull hard on it.

Very rare bracelet piece, you won’t find another one like this