Good quality pulleys and I am very happy with the product. Eight out of ten roll very smoothly and the other two are only slightly less smooth but probably still within tolerance. In general they are very good for the money. I'm particularly pleased with the center hole. I used to have pulleys where the wheel and bore were so thick that it was impossible to tighten them without restricting rotation. These wheels are thinner than the hole diameter, which allows me to clamp them without sacrificing rotation.