The objectives in developing the ­AP-1019E / F air purifier were a restrained design focused on the core functions paired with a discreet colour scheme. Using a four-step filter system, the device reliably cleans the air from pollutants in rooms of up to 33 sqm in size. The current air quality is measured in real time and displayed through three-step colour changes. The performance of the air purifier automatically adapts to the ­prevailing indoor air pollution level.