2/4/8 TimerSet a timer for 2, 4 or 8 hours to perfectly fit for your schedule. Maintain powerful purification when necessary, and save energy when sleeping or going out. | Filter Change ReminderThe Display/Filter button, with its red button light, reminds you the time to change filter after 3-5 months of use, depending on your usage. Search for "B09R1NNPJV" for purchase of official filters. | 3 Fan SpeedComes with 3 adjustable fan speed settings from Low, Medium to High, to find your optimal fan speed to tackle different purification needs. |