This is a nice heavy set of caster wheels. It can hold a total weight of 650 pounds. The wheels are a nice polyurethane material that won't mark or wear my hardwood floors which is what I was looking for in a new set of wheels. My old ones have removed the top layer of my hardwood flooring damaging it in spots where my wheels made contact with the floor in several spots. I had to do something before it ruined them. Instead of replacing the whole expensive chair I found that by purchasing these wheels it saved me money and my floors. I like how these wheels glide so smooth with no scratching or hitching. The wheels have precision ball bearings in the caster. They make no noise and leave no marks on my floors.