Hi, Use these new filters for my bench top unit. Don't do much wood or metal work. I do church widow restoration, so it's really glass. One of the painting (glazing) techniques used creates a cloud of toxic dust. Note the dirty filter, which is one of the new one just installed. I'm sure they didn't used any kind of filter in the old days. Can tell you that the old studios were really bad. Thanks to your unit I figure I've added a few more years on to my life.