The caliber Junghans J90 is the big brother of the Junghans J91, seen here in comparison. On the left side the J90, on the right side the J91. Both are men's watches.
The caliber Junghans J90 and J91 are the only built by Junghans watch movements with cylinder escapement. At that time it was thought that many watchmaker comes cope more easily with a simple cylinder escapement.
The above shown watch is the version with 6 jewels. Here you can find the version with only one jewel: Junghans J90 one (1) Jewel