The Speedmaster was introduced in 1957 as a sports and racing chronograph, complementing Omega’s position as the official timekeeper for the Olympic Games.  Its iconic place in history stems from its utilization by NASA for the Gemini Titan III crews and eventually by the astronauts on the Apollo 11 mission, which made it the first watch to be worn on the moon.  The Ref 3575.20.00 was in production for a limited time, from 1999 to 2003.

The Speedmaster Professional Moonphase has a 42 mm Stainless Steel case with an 18K White Gold tachymeter scale bezel.  The timepiece features a domed sapphire crystal and is powered by a Calibre 1866 Omega in-house movement.  The Moonphase has a 48-hour power reserve and is water resistant to 30 meters.  

This Omega Speedmaster Professional Moonphase is in good condition, with some wear consistent with the age of this timepiece, which is visible in the photographs.  The case back has yet to be removed on this piece, as evidenced by the factory red dot, which is still intact. This timepiece comes with the Omega stainless steel bracelet with 840 end links.