Made of solid cast iron with a 1-inch center hole, it fits standard bars with diameter of 1". It can also be used with 1" dumbbell bars. All plates feature a durable gray baked enamel finish to prevent the plates from rust and corrosion without any unpleasant odor. Each plate has 3 large openings with strips on them for easy grip, labeled in both lb and kg for easy recognition. Weight plates can be used to perform muscle-strengthening exercises, endurance training, or to increase flexibility and balance. Multiple weights are available: 160LB Set.