Wearing this Leonidas automatic today. It was part of a lot of watches I saw being auctioned online a few weeks ago for "beer money"....I didn't have a Leonidas in my collection, so took a chance. Just back from my WM, Mac...cleaned up nicely. It's powered by a Felca 690 Bidynator. Leonidas was, perhaps, best known for its chronographs. The company merged with Heuer in 1964, and production was branded Heuer-Leonidas for several years afterwards. The Leonidas name essentially disappeared when Techniques d'Avant Garde bought the company in 1985 and changed the name to TAG Heuer. Here's a link to an article about Leonidas watches for those wanting to learn more about the company https://thewatchforum.co.uk/index.php?/topic/121576-leonidas-watches/.