iwc Ingenieur Chronograph Mode D'emploi page 20

Functions of the crown
Normal position
This watch has a screw-in crown. The screw-in connec-
tion (normal position, position X) prevents unintentional
adjustment of the time and the watch case has double
protection against penetrating water. To release the
secure crown, unscrew it by rotating it to the left, where
it automatically assumes position 0, the winding posi-
tion. By depressing the crown in position X and rotating
it to the right at the same time, it is screwed down firmly
again and secured.
X 0 1
X Normal position
(screwed in)
0 Winding position
1 Time setting