Product review (5 stars): Much better then what shipped with my Vornado
These things are thick and thirsty. They put more humidity in the air and faster then the filters that came with my Vornado Evap40. My original filters (that shipped with the Evap40) struggled for days to push the humidity level from 20% to 45%.

I live in a 1,000 sqft  apartment in Chicago with very hard water and radiators. I had to turn off the humidifier while I was on vacation and returned to a very dry apartment at 10% humidity. I decided to try these new filters and within 8 hrs the humidity rose from 10% to 47% humidity!

These filters are be made out of more absorbant material then the originals and are maybe 1/4-1/2 thicker then the ones that come with it.

Note: These also aren't listed as compatible with the Evap40- but I assure you they are. They seem to be not wide enough by about 1/8-1/4 but they are so thick they can be gently stretched once they are fully wet to make up for the gap. It's always best to lightly hold a filter under running water and make sure they are thoughtly wet on both sides before you place them into the humidifier. They will become very full of water and be fragile- be careful not to crush them as you hold them to keep the air from being able to be pulled through them- and only stretch them carefully. Then place them on a plate or bowl and carry them to the humidifier to avoid dripping.

My suggestion would be ditch the standard filters immediately and get these. They are half the price and work twice as good.