Product review (4 stars): 6 inchs were great 8 inch ring warped..fixable
6 inches rings and pans are great = 5 stars. The 8 inch trim ring was somewhat twisted and burner would not lay flat. I straightened about 95% and installed 2 grooves for the other 2 burner flanges. Now burner lays flat and is stable. Customer service contacted me asking me about my experience. They wanted some pics but at this point the warp would not have been noticeable in a pic. They did refund $10 of the purchase price. In looking through reviews I did not see any others noting this issue so I do not think it a problem that occurs very often.