Seiko Prospex

The Seiko Prospex, reference SPB485JC, has a 41.3 mm steel case. The case is 12.5 mm thick, with a lug-to-lug measurement of 48.2 mm. Self-winding calibre 6R55 contains 24 jewels and has a power reserve of approximately 72 hours. The watch has a folding clasp with push-button release and an extender. LumiBrite is applied to the hands and indices. Movement accuracy is plus 25 to minus 15 seconds per day. The case has a screw-down crown; the watch has magnetic resistance. A sapphire crystal with an anti-reflective coating on the inner surface covers the dial.