Product review (3 stars): Worse yet, it collapses into itself
It dries up on the top, so you have to flip it over every night. Worse yet, it collapses into itself, limiting the amount of airflow, and thus lowering how much humidity is generated by the machine (I have a humidity monitor, and the same machine was considerably more effective with the Honeywell brand filter than with this one... unfortunately, since this one is considerably cheaper).