The King Seiko Special Hi-Beat Chronometer. This masterpiece from September 1972 Serial: 290888 is a rare double-badged treasure, featuring both the Special designation and an official Chronometer certification, representing the absolute pinnacle of Daini Seikosha's engineering. It houses the iconic Caliber 5246, a high-frequency automatic movement renowned for its incredible accuracy and slim profile, which eventually became the foundational architecture for the modern 4S series.

The architecture is a masterclass in 1970s functionalism, utilizing a robust "one-piece style monobloc case designed for superior water resistance and structural integrity. The dial is a work of JDM art, featuring a subtle linen-brushed texture, sharp baton indices, and the prestigious Daini lightning bolt logo. Flipping the watch over reveals the unique external regulator screw between the lower lugs, allowing for precision timing adjustments without opening the case a hallmark of Seiko's most advanced professional-grade instruments of the era.