I purchased 12 of the 13 Ball Nylon Garage Door Rollers that were very well priced. They appear to be good quality. It is the sealed type bearings. Only time will tell if the nylon will stand up to use I put them through. At the price I purchased them I got two extra just in case. They are already much quieter than the metal rollers. The older ones had been on their for at least 15 years and if these last that long, the next owner can replace them.
Exactly what I needed, high-quality, so affordable, fast shipping and exactly as described.
Now I can step the garage down that last little bit & latch it without pushing on the handle to do it.