Seiko Instruments Inc. VK63A

The VK63A is a quartz mecaquartz chronograph caliber manufactured by Seiko Instruments Inc. It features sweeping seconds, a characteristic uncommon among quartz movements, achieved through the mecaquartz design that combines a mechanical chronograph module with a quartz timebase. As part of Seiko Instruments' in-house VK family, the caliber remains in production and is used primarily in the brand's own watch models.