Armin Strom STROM-ARF21

The Armin Strom ARF21 is a hand-wound mechanical movement developed in-house from the ARF15 and finished in Switzerland. It features Incabloc shock protection and is characterized by dual balance wheels connected through Armin Strom's patented Resonance Clutch Spring, which synchronizes the oscillators in opposite directions to improve rate stability. The caliber is used in the Mirrored Force Resonance line, with a variant designated ARF21_ZG featured in the Resonance Zeitgeist model.