Ducati MONSTER 821 Workshop Manual page 376

REFITTING THE LEFT-HAND SWITCH
Connect the left-hand switch to the main connection and position it on the handlebar.
Fasten the left-hand switch by tightening screws (1) to a torque of 1.3 Nm ± 10% following the 1-2-1
sequence starting from the upper screws.
Left-hand switch position is mandatory: pin (C) must be inserted inside hole (D) of handlebar (8).
376 Ducati Manuals Resource