Product review (4 stars): For mini humidifiers
These are for mini-humidifiers. The following products would use them.

http://www.amazon.com/AGPtek%C2%AE-Humidifier-Bedrooms-Living-Office/dp/B00GSKCWL6/ref=sr_1_1?ie=UTF8&qid=1446040223&sr=8-1&keywords=mini+humidifiers

OR

http://www.amazon.com/gp/product/B00OH1TXGK?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s02

There are other, newer ones humidifiers on Amazon that I cannot speak for - these were just some I ordered in 2014. It is kind of hard to figure out which ones you need as I have some other mini humidifiers that use similar but different length or different width filters.