NEC PA721X User Manual page 170

7. Maintenance
Cleaning the Filters
CAUTION
1. Push up the buttons on the left and right to release the
filter unit and pull it out.
2. Remove the filter unit by pulling out the tab.
3. Remove the four filters.
(1) Turn the filter unit over and pull out the two soft accordion
filters.
Filter cover
Filter unit
158
Button
Tab