Product review (1 stars): Filters Are Fragile and of Very Poor Quality!
As boxes of filters arrived crushed, filters were broken.  IMO insufficient glue is used to assemble the filters, so they fall apart when stretching them to fit into the humidifier.  Had to block the openings left between the ends of filters and the filter holders to prevent air from passing around filters.  Bottom line is that filters were a real PITA to install and openings reduce the effectiveness of the humidifier. I would NOT buy them again.