The OMEGA SpeedMaster Professional "moonwatch" is a historical, significant piece of horology and NASA space/moon exploration that you can wear on your wrist! While Rolex has also spent time in space via their GMT model the SpeedMaster was the first watch on the moon and used to help time rocket burns. It is tough and accurate. Mine has been running +/- 5 seconds/day and while it's strange to wind my watch by hand after being used to "automatics", it has earned a place on my wrist for life. This model is a must have for any true watch collector OR space exploration, Apollo Mission, history buff.