Omega Speedmaster Automatic Mark 4.5 Ref 176.0012

The Omega Speedmaster Mark 4.5 ref. 176.0012 is a distinctive expression of the Speedmaster’s 1970s evolution, blending bold design with proven chronograph performance. Produced in the late 1970s, this reference features a robust tonneau-shaped stainless steel case and an integrated bracelet that reflects the era’s utilitarian aesthetic. At its heart is the Omega Caliber 1045 automatic chronograph movement, based on the Lemania 5100, renowned for its durability and legibility, including a central chronograph minute hand ideal for precise timing. While not officially a Mark series watch, the Mark 4.5 earned its moniker for Omega's blending of the Mark 4 case with the Caliber 1045 movement found in the Mark V timepieces.  With its racing-inspired dial, day-date display, and unmistakable wrist presence, the Mark 4.5 stands as a compelling chapter in the Speedmaster lineage and a favorite among collectors of vintage tool watches.