Paralympic Games. Apart from them and record discs, IPC approved set uses the same plates as the IWF one. Technically, and smaller plates can be of any colour in IPF approved sets, although only colours listed above were used for them by few certified manufacturers. Non-competition equipment Most "Olympic" bars one can see in commercial gyms, although superficially similar to real Olympic bars to the untrained eye, do not share International Weightlifting Federation or powerlifting essential characteristics. They are just generic strength training bars, with wide variations in markings, grip section diameter, and exact weight. Weight plates used outside of competition need not conform to IWF or powerlifting specifications, and can be of any colour. Kraiburg bumper plates are rated in pounds, and one notch lighter than expected, regarding their traditional place in colour code: red plates are , blue ones , etc. Collars Standard collars can be of any material, usually metal, and they can weigh up to each for both men and women. Typical Olympic bar with a pair of collars, the plates not counted, can weigh as much as for men and for women depending on the collars. Other types of Barbells Berg Prototype "Olympic" revolving Barbell This barbell was produced by the company Berg in 1910, but designed by Veltum. This was a major turning point in Olympic lifting as the barbell was able to revolve easily during the lift. After the Olympic games in 1928 Amsterdam, the barbells began to become popularized and many companies started to copy the barbell. The Berg barbell and copies of it were spread through many gyms around the world mainly from the 1960s to the 1970s because of the rise of the new barbell. "Standard" or "One Inch" Barbells "Standard" or more commonly "One Inch" or "1 inch" barbells are characterised by a bar that is very approximately one inch (25.4mm) in diameter along the whole of its length, with a commensurate sized centre hole in the weight plate. Despite the "Standard" name they come in a wide range of sizes that can have little in common with one another, and usually range from 25mm (0.98in) to 29mm (1.14 in) in diameter in varying lengths and other dimensions. In contrast with the rotating sleeves and uniform sizes of Olympic bars, which mount plates with a fixed size centre hole; the ends of standard bars do not rotate, and commonly