A ref. 2915 Speedmaster, the first of all Speedmaster references made from only 1957 until 1959. The 2915 features a 38.5mm straight-lug case, highly-legible dial with broad arrow handset, and calibre 321. It was also the first chronograph ever with a tachymetre on an external bezel. This is a 2915-2 from the middle of production, featuring the highly desirable steel base 1000 bezel which is original to the watch. Its dial features the characteristic wide O of Omega and fantastically tan, nearly orange plots. Omega advertised the 2915 in period as the watch, ‘For men who reckon time in seconds’. That holds true still today.