When I wiped the inside back perimeter of the dryer drum with a clean cloth, I got the same mark as on my laundry. So, I researched the problem online and found the same problem description and a solution on your appliancepartspros.com website. I watched the video and it looked like something I could fix myself. So, this daring, 70 yr old woman, ordered the part, used the video step by step and replaced the felt drum seal myself! The dryer works better than ever (quieter and faster) and no more marks. Only minor issues were the drum practically fell out as I was removing the front panel, so I had to manage holding onto both at the same time. When I put the drum back into the unit, I put something under it to hold it in place until I reattached the belt. Otherwise, it went as described in the video.