Our gym was using basic cast iron 2.5 and 5 pound plates, but we wanted some change plates that wouldn't do damage to the bar. These appear to be very solid and should last a very long time. Now we won't have to worry about nicking up expensive bars with cheap plates. These are a great value for complete rubber change plates. I had considered some by other companies, but in the end they were just rubber-coated, and more expensive than these. To top it off, shipping was super fast and I received the plates in about 2 days. I read about these plates on another site, and had never heard of Vulcan honestly. I'll definitely be checking out Vulcan for future needs!