The induction of the outside air and expelling stale air in the cab interior can be selected by turning the switch. Roof ventilator OPT Remove the key when leaving the vehicle to avoid unintentional window operation by children. - 2–38 - CONTROLS AND INSTRUMENTS When the power window lock switch is in the "ON" position, you cannot open or close by means of the power window switch on the driver’s door or passenger door. Press the lock switch once again and the power window will be unlocked. To ensure the safety of children and others make sure that all passengers have their hands, etc. inside the vehicle before Power window lock OPT WARNING closing the windows.