Ducati DIAVEL Owner's Manual page 163

Helmet cable
Note
Helmet cable can be found inside the tool kit.
Route cable through helmet and engage cable end
into pin (3). Leave the helmet hanging and refit the
seat to hold it in place.
Warning
This device protects the helmet against theft
when the motorcycle is parked. Do not leave the
helmet attached when riding the motorcycle; it could
interfere with your movements and cause loss of
control of the motorcycle.
162
3
2
Fig. 114