They filter well and catch a lot of dirt and dust. You can take them off and shake off most of the accumulated dirt and dust and then put them back on so they last until you get wet. Installation is easy if you press them all the way down so the filter hole protrudes over the edge of the pin they attach to. Otherwise they just fall off, then you will notice early enough when what you are sucking is being blown out again. It takes some effort to push them all the way through.