Product review (3 stars): Works fine in HCM350, a bit less longevity than name brand filters.
Use this with a Honeywell HCM350 humidifier. I've tried several oem and third-party filter material, and these fit just as well as factory. In terms of longevity, these seem to work at peak efficiency for about two weeks, running continuously. After that, the consumption of water drops markedly despite similar conditions. OEM and other filters seem to last a bit longer before loosing efficiency and getting 'crusty.' Given that these are so much cheaper than the Honeywell filters, I'll continue to buy third party filters, but I'll just pick whichever are cheapest.