Own a piece of horological history. The Seiko 6139 movement is world-renowned as one of the first automatic chronograph movements ever produced (released in 1969). It famously features a column wheel and vertical clutch—high-end engineering that many Swiss brands didn't implement until decades later. This specific caliber, the 6139B, is the refined, high-performance evolution of that legendary movement. The "Hexagon" Design The 6139-7080 is celebrated for its bold, architectural hexagonal stainless steel case. This model perfectly captures the "space-age" aesthetic of the mid-1970s. With its integrated-style lugs and sharp geometric lines, it offers an incredible wrist presence that feels both vintage and strikingly modern. Condition Report • Movement: Caliber 6139B. Recently professionally cleaned and oiled. It is running accurately and keeping excellent time. The chronograph functions crisp, and the sub-dial resets perfectly to zero. • Dial & Hands: A stunning deep matte black dial featuring the iconic "Suwa" factory logo. The blue tachymeter ring provides a sharp, sporty contrast. The hands and markers remain in excellent vintage condition. • Crystal: Fitted with a scratchless crystal, ensuring a crystal-clear view of the dial and sub-register. • Case: The 40mm stainless steel case retains its original sharp edges and "brushed" finish on the top facets. As seen in the photos, it shows honest signs of wear (fine scratches/flea bites) consistent with its 50-year history, preserving its authentic vintage character. • Bracelet: Comes on its original Seiko-signed stainless steel bracelet with the correct folding clasp. It is rare to find these with the original band intact. Technical Specifications • Reference: 6139-7080 • Serial Number: 520373 (Dating the watch to February 1975) • Case Diameter: 40mm (excluding crown) • Functions: Hours, minutes, 30-minute chronograph, Day/Date (Quickset working) • Movement: Automatic 17-Jewels 6139B • Material: Stainless Steel Collector's Note The 6139-7080 is becoming increasingly difficult to find in original condition with a clean, serviced movement. Whether you are a seasoned Seiko enthusiast or a first-time vintage buyer, this "Hexagon" is a robust, historically significant timepiece that is ready to be worn and admired.