I kinda knew the answer to the above question but since I don't use a household vacuum very often (I usually use a shop vacuum) I never thought of replacing filters with a house vacuum then I did used it for the first time in a long time and noticed that the suction power is less than it should be. Anyway, I figured out the problem with the filter. Thanks to these easily replaceable and inexpensive filters, our vacuum cleaner works like new again.