This fantastic piece, produced in the late 1960s, is a Heuer Autavia Chronograph 2446.  I was fortunate enough to inherit this piece from my late father, who inherited it from his own father in 1980.  Many will not recognize the brand, and that stands to reason, given that it no longer exists.  The Heuer Watch Company was started by Edouard Heuer in 1860 & over a century later merged with the TAG group (Techniques d'Avant Garde Group) in the mid 1980s.  While the current TAG Heuer company is certainly a respectable and important watch maker, it is the classic Heuers (pre the merge with TAG) that are truly collectable among watch collectors, as they retain the original aesthetic and styling of the origin brand.   

The 2446 is a stunningly beautiful watch that could probably serve any occasion.  One could easily wear such a piece on a daily basis or with a suit/tuxedo (especially with the steel bracelet).  It was originally created to serve either a pilot or a diver & as such was sold with either a stainless steel Gay Freres "beads-of-rice" bracelet (for the diver) or with a leather rally band (for the pilot).  The Heuer watch company was renowned for its involvement in racing & timing events (including aviation speed testing), and took pride in their watches being considered accurate enough to serve European & American racers.  Thus, the name "Autavia" is an acronym for "Automobile" & "Aviation".   Autavias are exceedingly rare watches; odds are that if you see one on the street somewhere, it belongs to a vintage watch enthusiast.