Not all bumpers are created equal. Here's why your next bumper plates should be Fringe Sport bumpers: Fringe Sport bumper plates feature a steel insert that is designed to far outperform the brass bumpers used by the competition. A steel insert will take much more abuse without malforming- and it is machined to exact tolerances to fit all high-quality Olympic bars. Fringe Sport bumpers use a rubber formulation that combines the ideal mix of_low bounce with high durability. Some bumper plates bounce too much- they are potentially unsafe. Other bumpers are too brittle- and they easily chip and fall apart. Not Fringe Sport bumper plates! Fringe Sport bumpers 10 and 15 pound bumpers are more stable because they have a high durability, "hooked" steel insert. This makes them more stable than most 10 or 15 pound bumpers- which are the most fragile bumper plates due to their thin-ness. Fringe Sport bumpers are thinner than many of the competing bumpers- so you can load more weight on your bar! Fringe Sport bumpers all have the same standard diameter- you can mix and match to load your bar. Finally, Fringe Sport bumper plates are backed by our no-questions-asked satisfaction guarantee- plus a 1 year warranty from the manufacturer. Use them and love them- or send them back free!