Product review (5 stars): it was easy to reshape them into a cylinder again and they ...
I bought this filter in a two pack, so, to get both filters in the same box, the filters were flattened.  However, it was easy to reshape them into a cylinder again and they fit the humidifier perfectly.  I have every expectation they will get me through the winter until I can turn the furnace off and open the windows to fresh air and natural humidity.  I recommend this product.  Very functional at a good price.