Omega Speedmaster Mark IV | 4.5 Automatic Chronograph | Ref. 176.0012

About This Watch

Omega Speedmaster Mark IV 4.5 Automatic Chronograph | Ref. 176.0012 | Caliber 1045 The Omega Speedmaster Mark 4.5 (ref. 176.0012) is a vintage automatic chronograph that blends classic 1970s design with modern (for its era) mechanical reliability. It uses the robust Caliber 1045 (Lemania-5100 based) automatic movement, delivering day/date, 24-hour indication, and chronograph functionality. Though unofficially dubbed “Mark 4.5” by collectors, the 176.0012 pairs the case style of the earlier Mark IV with the automatic movement of later Speedmasters — giving it a unique place in the Speedmaster lineage. Technical Data • Reference: 176.0012 / ST 176.0012 • Movement: Automatic — Caliber 1045 • Functions: Hours, minutes, small seconds, day, date, 24-hour indicator, chronograph, tachymeter. • Case Material: Stainless steel • Case Size: 42.0 mm • Dial: Black • Crystal: Mineral glass • Bracelet / Strap: Stainless steel bracelet • Water Resistance: Not Guaranteed on Vintage Watches