'88 until '94. It houses the 889, and was a thin water watch with uni-directional bezel, meant to go up against the Aquanaut. The bracelet is one of the MOST comfortable I've ever had the pleasure of wearing. Within the Kryos family, they also offered the Cal 63X with mecha-quartz movement. Although small by today's standards, it fits nicely under a French cuff.
If you send it to JLC and ask for a full overhaul, it'll come back looking gorgeous with the wide links being brushed and the narrow links being polished.
Great find.
-Dean