Armin Strom’s most advanced base movement since its first in-house caliber was originally introduced in 2010. In addition to displaying the hours and minutes centrally, and the small seconds off-center to the left, there’s an Up/Down power reserve indicator at 11 o’clock on the dial side. Twin mainspring barrels mounted in series allow movement to run 168 hours (7 days) on a full wind and with better than chronometer accuracy across the full powerband.

Caliber: ARM21

Release Date: 2023

Country: Swiss made

Type: Manual Wind

Dimensions: 36.60 mm/6.00 mm

Total Components: 194

Jewels: 26

Oscillating Frequency: 3.5Hz (25,200 VPH)

Power Reserve: 168 hours

Functions: hours, minutes, small seconds, power reserve indicator

Balance Wheel: Variable inertia, free-sprung with Breguet overcoil

Finishing: Geneva stripes (manual), perlage (manual), perlage (manual), beveling (CNC and by hand), polishing by hand, straight graining, frosting

Unique Features: twin power barrels mounted in series, cone style power reserve indicator, openworked movement