Rubberized plates are flat, heavy objects that are used in combination with barbells or dumbbells to produce a bar with a desired total weight for the purpose of physical exercise Two general categories exist: “standard” plates, which have a center hole of approximately 25 mm (one inch), and “Olympic” plates, meant to fit on the 50 mm (two inches) sleeves of Olympic barbells Weight plates are typically round, although 12-sided and other polygonal varieties exist
