Dont know what i gotplain box filters are unmarked could be 3 dollar version you buy at the supermarket they used to be individually wrapped last order i got today they are in a box i would think the filter gets dusty before you would even install quality is good for filter we use one a month hiuse stays dust free and the unit stays efficient but will not buy again from here a little too small i had to shim it in to keep there from beimg thin line gaps