Seiko SSA381

The Seiko reference SSA381 has a steel case measuring 42.4 mm across. The case measures 14.5 mm thick, with a water-resistance rating of 100 metres. The movement is self-winding calibre 4R37, which contains 24 jewels and has a power reserve of approximately 41 hours. The dial is covered by a curved Hardlex crystal. The watch has a three-fold clasp with a push-button release mechanism. The movement is visible through the display back of the case. The case has a lug width of 21 mm. The hands and indices carry LumiBrite.