1 Stable Ergonomic Structure ，Allocate weight on Ergonomic Structure.Deliver stabilized， concentrated workout. 2 Strong Chrome Steel ，Steel Bar diameter of 20mm (~ 7/8 inch) or the Classic or 25mm (1 inch) for the Ultra . Each bar can hold 100kg (220lb) for the Classic or 150kg (330lb) for the Ultra 3 Foam Kneepad，High-density foam kneepad for protective workout