Product review (4 stars): Fits into the Holmes HM-3500 humidifier like a glove
Fits the Holmes HM-3500 just right.  The package said it would.

Seems well constructed.

I'm not sure the blue outer surface does anything significant.  Even if the blue webbing is completely "anti-microbial," how does that keep microbes from flourishing in the other 99.99% of the wick?

The dewpoint [outside] was in the upper 30s, my apartment is about 700 sq. feet, and my humidifier was coming on almost constantly.  It should have been coasting along (with the fan on Low) instead of stressing.  I took out the old filter, put in one of these, and with the same dewpoint, the humidifier comes on for much less time, saving electricity and my patience.

Now, I'm ready for 0 Degree dewpoints -- Bring it on.

I recommend using a mineral-dissolving Water Treatment so your wick lasts for 6 months instead of 4 weeks.  I have soft water, but use a little squirt of Treatment every time I add a couple of gallons of water, regardless.  I think it helps extend the wicks' life.

Lose one star:
* for not being 100% antimicrobial but including marketing jargon that implies that it is
* for not lasting forever, and
* for costing too much.