Product review (1 stars): Lasts about a week
I ordered four of these direct from Holmes.  Together, they lasted a total of 3 weeks.  I have the HM1895 humidifier with the filter gauge.  The first one lasted a week.  The second one lasted a week and a half.  The third one lasted 2 days.  The fourth didn't work at all, the gauge never got above the "change" line.

I've since tried a universal third-party filter&nbsp;<a data-hook="product-link-linked" class="a-link-normal" href="/BestAir-Wick-filter-fits-Holmes-H65-ID/dp/B004Q07Z62/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">BestAir Wick filter fits Holmes H65-ID</a>.  This worked for a month, which is the expected life.