The Omega Speedmaster Professional Chronograph was the first watch on the moon, worn by Neil Armstrong and Buzz Aldrin. Armstrong's watch is now displayed at the National Air and Space Museum in Washington D.C. Aldrin's is believed lost. He mentions in his book, Return to Earth, that when donating several items to the Smithsonian Institution, his Omega was one of the few things that was stolen from his personal effects.
In 2007, to mark the 50th anniversary of the Omega Speedmaster Professional Chronograph, the Omega company unveiled the commemorative Speedmaster Professional Chronograph Moonwatch. The watch had the distinctive features of the first hand-winding Omega Speedmaster introduced in 1957. It was sold in an edition of 5,957.
Omega Speedmaster is a brand of chronograph wristwatches produced by the Omega Watch Company. Many different watches have been marketed under the Speedmaster name over the years. The manual winding Speedmaster Professional or Moonwatch is the most well-known and longest-produced; it was worn during the first American spacewalk during Gemini 4 and was the first watch worn on the moon during Apollo 11. The Speedmaster Professional remains one of several watches qualified by NASA for spaceflight and is still the only one so qualified for EVA. The Speedmaster line also includes a multitude of other models, including analog-digital and automatic mechanical watches.
To reinforce the association with astronauts, Omega also began using the Professional appellation for existing Speedmaster models after Gemini 4. In 1966, Speedmaster reference 105.012 was updated to reference 145.012. These two models would be the two Speedmaster references known to have been worn on the moon by Apollo astronauts, the original moonwatches.  Speedmasters were used throughout the early manned Apollo program, and reached the moon with Apollo 11. Ironically, these and prior models are informally known as Pre-moon Speedmasters, since their manufacture predate the moon landings and lack the inscription subsequent models carry: The First and Only Watch Worn on the Moon .