This is a nice Sandoz vintage tank watch from the ca. 60's - 70's with a mechanical 17 jewels movement (Felsa 780?).
Info about the specs of the Felsa Cal. 780; here.
If you want to read more about the history of Sandoz; here.
A 1968 magazine ad of Sandoz watches in Persian 🇮 🇷, Zan-e Rooz .