This is a 1950-60s (more likely 1950s) MuDu wristwatch with a 25 jewel Doublematic movement. It has a fairly unique metal mesh band that clasps securely around the wrist. It was gold-plated but most of that has worn off. I’ve had it cleaned, serviced and polished and it looks pretty good now. I’ve also had indentations refiled in the crown, because it had become so worn that I couldn’t adjust the time anymore. It works great now. I like MuDu watches, they’re affordable and fun to collect.