Seiko SSB321

The Seiko reference SSB321 is a chronograph with a 43.9 mm steel case. The case measures 12.9 mm thick, with a water-resistance rating of 100 metres. Quartz calibre 8T67 has a battery life of approximately 36 months. The dial is covered by a Hardlex crystal. The clasp has a three-fold construction with push-button release; the hands and indices carry LumiBrite. Movement accuracy is plus or minus 15 seconds per month. The lug width measures 22 mm; elapsed time is measured in increments of 1/5 second. The dial has a date display and a tachymeter.