The Omega Speedmaster 57 Co-Axial Chronograph reference 331.10.42.51.01.002 represents the modernized 2015 evolution of the original CK2915 Speedmaster from 1957, the very first Omega chronograph designed for motorsport timing rather than aviation. The reference re-introduces the two-counter dial layout of the historical CK2915 alongside a contemporary 41.5mm steel case, broad-arrow hands, and an applied Omega logo, blending mid-century cues with current manufacture-grade movement architecture. The black brushed dial carries beige transferred dial indications for a warm vintage feel, with a small seconds sub-dial at nine and a combined 12-hour and 60-minute chronograph register at three, the latter consolidating the traditional three-counter Speedmaster layout into a more legible two-counter format. Powered by the in-house Omega Caliber 9300, the first chronograph in the brand's Co-Axial in-house family, beating at 28,800 vibrations per hour across 54 jewels with twin barrels delivering an approximately 60-hour power reserve, ISO 3159 chronometer certified. Water resistant to 100 meters with a sapphire crystal caseback. The 331.10.42.51.01.002 sits as the modern Speedmaster '57 catalog reference alongside the broader 41.5mm Two Counters family. Pre-owned condition.