Armin Strom's signature resonance line, introduced in 2016: two independent balance wheels, staged prominently on the dial, are mechanically coupled by the brand's patented Resonance Clutch Spring so they synchronize with each other for greater rate stability. A twin-seconds flyback lets both running-seconds hands be reset together without stopping the movement.
enthusiastmodernArmin Strom Cal. ARF21 -- manual-wind, in-house, two independent balance/regulator systems connected by the patented Resonance Clutch Spring so they synchronize; 25,200vph, 39j, 276 parts, two independent barrels, 48h PR; twin-seconds flyback resets both running-seconds hands simultaneously without stopping the movement43mm2023–present
