For those interested in the Oyster Quartz Datejust. This is an update on my 1990 OQ, that RWSC Dallas did a complete overhaul several months ago. It is the model 17013, two-tone. For accuracy buffs, or fanatics, it has lost only 17 seconds since received from Dallas. I can live with that. Running flawlessly. I've been wearing it 23/7, since it came back. I will not wear it in the shower, reason, soap scum, although it's water resistant to 330 feet like any other Datejust, mechanical or quartz.