Product review (3 stars): Somewhat disappointed in the lifespan of these 'extended life'
They do a decent enough job, but seem to require replacing more frequently than I recall when I was able to use original Sears-brand filters. I use these with a Sears humidifier, which we use during the heating season (forced air heat dries the air). The humidifier has a sensor to let you know when the wick needs changing - presumably based on some kind of sensor that determines how much water is flowing through the system over a given period of time. When I first bought the humidifier and bought Sears replacement wicks, they tended to last for an entire heating season before needing replacing. These wicks seemed to only go for 2-3 months before needing replacement (ironic since they're marketed as 'extended life'). Unfortunately, it seems to be the only brand I can find that fits my humidifier, but if you have a choice with yours, I'd consider trying the other option first.