I bought a different device from a different manufacturer but it was so big, so heavy, so ugly, and so loud that I couldn’t stand it and returned it. I chose this model for its fetching design and size and I love it! I still haven’t read the instruction booklet so I don’t know what I don’t know about it. I think it’s working great—I love looking at it and it’s very quiet. If I’m stirring up dust by shaking something out, I hear it rev up to a higher speed,