Interesting ebay find.. This chronograph watch reached me just in time, when I finally managed to get the back off the battery was just beginning to leak, but no damage had been done. The bezel took a while to turn and click, but now works fine. After replacing the battery I found instructions for a 6850 G8 1155. and to my surprise I was able to carry out a reset, then set the time and Calendar.by using the bottom function dial. The calendar is interesting in that when you set the function pointer to cal, the small second hand indicates the month, and the large second hand indicates the the date on a scale outside the dial. I am quite pleased with this one. I have no idea of the age but it is in remarkable condition.