From the first year of production to about the end of production.Just got my depollier case Illinois out of the shop.There are a lot of problems with the stem and crown on this type of case the stem is longer and the sleeve falls apart and then there is a spring that goes over the stem I have talked to others that own them and they ask if I have problems with the crown I took it to two differnt watch maker's the second one was able to fix it work great now.