Product review (3 stars): These don't last long.  They fit the humidifier though.
These don't last 30 days.  They get discolored within 2 weeks and start to get moldy/mildewed by 4 weeks.  We remove the filter every morning and set it on the counter to air dry and dump all of the water out of the base of the humidifier but these don't last as long as they say.  Kinda disappointing.