How does the Auto-off Timer work, and is it available on the HPA090?

The Timer Option is not available on the HPA090 Series. On compatible models, tap the Auto-off Timer icon to cycle through three pre-set run times: 2, 4, and 8 hours, and an LED will illuminate to indicate the selected time. The unit will automatically shut off after the chosen run time; do not use this option if you want the unit to run continuously. (Page 3)