Thank you for viewing. I used this on a soft mat, so I think there are almost no noticeable scratches or stains on the bottom of the main unit or overall. The line tensioning member (center of photo 4) has some scratches. A hamster chewed on it. Similar parts are sold in the lumber section of home improvement stores, so please purchase them separately if you are concerned. (⁠ー⁠_⁠ー⁠゛⁠)