Product review (2 stars): Be warned, the filter is a GENERIC replacement for the HAC504
OK, so I should have read the reviews before purchasing.  I would have seen from the first review that this is not made by Honeywell itself.

The product details says "Item model number: HAC504", the Honeywell model number.

I received a "Best Air HW500 Humdi-Wick".&nbsp;<a data-hook="product-link-linked" class="a-link-normal" href="/Best-Air-Humidifier-Filter-HW500/dp/B000UFQOOQ/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">Best Air Humidifier Filter (HW500)</a>

I don't like being bait & switched, so I am dropping the rating down to 1.

But the price for the HW500 with a few minutes of online searching was, at it's cheapest, $1.50 more, and even on amazon from a non-misleading item search, was $3.50 more.  And the company did ship pretty quickly; it arrived 3 days after the order was placed.  For that, I am raising the rating to 2.

I have no review on how well the HW500 will work in the Honeywell humidifier yet.  I am going to go ahead and use one for a couple of weeks to see how well it works.  I will say that the diameter is smaller the the HAC504, but I am not sure if that will make a difference.  If it works OK, I will come back and raise the rating to a 3.

To the seller:  To get any higher, I would need to see some indication in the main product item page that this is a GENERIC filter instead of a Honeywell brand item.