The Sea-Gull ST1901 is a 21 jewel column-wheel chronograph manual winding movement. It's operating at 3 Hz (21,600 vph), has a running second dial at the 9 o’clock position, a 30 minute counter sub-dial at 3 o’clock, and a sweep second counter mounted centrally along with the timekeeping minute and hour hands.

The chronograph functions are controlled through two buttons, one (at 2 o’clock) for starting and stopping the chronograph, one (at 4 o’clock) for resetting the second and minute counters. The ST1901 has many family members, a precise and strong running chronograph watch movement.

Model: Sea-Gull ST1901

Ruby Jewels: 21

Movement Calibre: 31.3mm，thickness: 5.85mm. Frequency: 3 Hz (21.600 vph)

Functions: hours, minutes, seconds, calendar, summing up stopwatch

Technical Specs:

Case Diameter (excluding crown): 38mm

Case Thickness: 14mm, Lug-To-Lug: 46mm, Lug Width: 20mm

Case Material: 316L Stainless steel

Movement: Seagull TY29

Frequency: 21,600 vibrations per hour

Water Resistance: 50 meters or 5 ATM

Mirror material: synthetic sapphire crystal