Olympic plate: The Sveltus TRAINING OLYMPIC DISC 5 kg x 50 mm is made of natural rubber and is designed for high impact exercises such as weightlifting and cross training. It has a hardness of 88-90° Shore A which minimises the bounce when it is dropped. The disc can only be used on weightlifting plates. For bars with a 50 mm diameter bar and has a 10 000 drop guarantee.