These seem to be top-notch quality pulleys. In particular, their ball bearings are snug, unlike the wobbly, loose-fitting bearings I bought from a major home supply store, that these are replacing.I will say a word about customer service. The original package was torn open in the mail and the pulleys must have fallen out because it arrived empty. Their customer service immediately sent me a replacement by priority mail, no questions asked.
I measured old spring and ordered a replacement from Preferred Doors. The spring took a few days to get due to supply chain delays these days. When it arrived, it was packed well, and it was what I ordered and expected. I installed it without any problems, and my door is working again. Time will tell how well it holds up, the old spring lasted over 10 years.