The Seiko Prospex Sea GMT SPB381J1 is perfect for both professional divers and watch enthusiasts. Whether you're exploring the depths of the ocean or going about your daily life, this watch is up to the task. It has a case diameter of 42mm, a thickness of 12.9mm, and a lug - to - lug measurement of 48.6mm. Its high water resistance makes it great for diving, and its reliable movement ensures it keeps good time in any situation.