http://www.jordanaheels.com In international trade, usually use the metric (Metric System), Imperial (The Britain the System), U.S. (The U.S. System) and the International Standards and Metrology organizations promulgated in the metric based on the International System of Units (The International of Unit). According to the provisions of the Metrology Law of the Peoples Republic of China: "the countries have adopted the International System of Units. Other units of measurement, the International System of Units units of measurement and the state selected for the national legal units of measurement." At present, in addition to particular areas, generally not allowed to use non-statutory units of measurement. Chinas export commodities, in addition to taking care of the other country trading practices agreed to the use of metric, imperial or U.S. units of measurement, the use of legal units of measurement. Chinas imports of machinery equipment and instruments should require the use of legal units of measurement. Otherwise, it is generally not allowed to be imported. If there are special needs, must also be approved by the Standards and Metrology management department. Different weights and measures result in the same units of measurement represented by the number of differences. For example, it means the weight of t in terms of the implementation of the metric countries, tonnes per tonne of 1000 kg; the implementation of the imperial countries generally use the long ton per long ton of I016 kg; the implementation of the American countries generally use short tons per short tons to 907 kg nike high heels .