Product review (1 stars): I'm MELTING!!!!!
I needed these to replace the original knobs on the oven that broke after many years.  They do not make the metal replacement parts anymore so I had to settle for these plastic knobs.  After about 3 weeks, the knobs closest to the back burners have started to melt (see melted know on left in picture).  Unfortunately, there are not a lot of other options.  I might try to find someone selling old, metal, used knobs.