iwc DA VINCI CHRONOGRAPH CERAMIC Operating Instructions Manual page 18

Functions of the crown
X
Normal position
This watch has a screw-in crown. Screwing the crown in to its normal posi-
tion (X) prevents inadvertent adjustment of the time or date and also acts as
a double seal against ingress of water into the case. To release the crown,
unscrew it by turning it to the left, where it automatically assumes position 0,
the winding position. By depressing the crown in position X and turning it to
the right at the same time, it is screwed down firmly again and secured.
Winding position
With the crown in the winding position (0), you can also wind the automatic
movement by hand. A few revolutions of the crown are enough to start the
movement. However, it is better to wind the movement fully by turning the
crown through about 40 revolutions. This will ensure maximum accuracy and
a power reserve of about 68 hours, even if you are not wearing the watch.
0 1 2
X Normal position (screwed in)
0 Winding position
1 Date setting
2 Time setting