So I ordered some of the aluminum trim rings to 1. keep my pads from rotating around in the cups and having to adjust them every time I wear the headphones, and 2. because I heard it can help get a better seal. Well, after removing the plastic one on the right side my screws no longer get any grip. The housing's threading is completely stripped. I am very upset about this as when I had my HE-300, which is a fraction of the cost of the HE-6, I took the plastic trim on and off several times and never stripped out anything. I sent them an email about it. Also, the aluminum trim rings aren't as thick as the plastic ones and end up sitting below the outer housing. So I'm not sure if that would really improve the seal as then there would be a gap between the trim and the plastic rings on the outer side.