Product review (5 stars): I think this order was a three pack. Initially ...
I think this order was a three pack.  Initially a reusable one was purchased. Don't do it.  This one has lasted longer than the reusable one so is more cost effective.  Watch your indicator.  It will indicate it is time to replace when the filter is dry.  Once you replenish the water supply the indicator will move back into the "good" zone.  Give it a few min after adding water.  I am still using the first one after, i think, 3 months.