ZČZ - Zlatoustovskij časovoj zavod - is a successor of a temporarly moved 1MČZ from Moscow to Zlatoustovskij during the second world war. After 1MČZ returned to Moscow, ZČZ stayed active as independent watch company. ZČZ was specialized in military program, most known watch is huge diver Vodolaz watch. From the civil production company was known for it's Agat stop watches. ZČZ also produced pocket watches, it's movement was to big for standard civil watches.
Company still exist, now it produce watches under the name Agat, it's main products are different versions of Vodolaz reissues. But one should be carefull since a lot of illegal replicas of Vodolaz were quite common in Moscow but they were easy recognisable since on the box Zlatousovskij was written instead of Zlatoustovskij (so t was missing).
ZČZ watches from USSR period
Agat watches from Russia