Definition: Compose a new way to ask the same question. The new question must be asking the exact same thing as the original question does. Without any other information, you should be able to tell that the original question and the new question are the same. Preserve bracketed phrases in your new question. You can change the rest of the question provided the above requirements are satisfied. The new question must have a natural, fluent formulation, as if it were composed by a native English speaker. You will be given three pieces of information to help you create better questions. Those are: "Answer": the answer to the question, e.g., "Honolulu". "Answer Type": the type of the answer, e.g., "Location". "Auxiliary Information" is a detailed description of some concepts mentioned in the question, if any.
Input: original question: Which measurement system use [Kilogram] as mass unit?
answer: international system of units
answer type: Measurement System.
auxiliary information: The kilogram or kilogramme, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype of the Kilogram. The gram, 1/1000th of a kilogram, was originally defined in 1795 as the mass of one cubic centimeter of water at the melting point of water. The original prototype kilogram, manufactured in 1799 and from which the IPK is derived, had a mass equal to the mass of 1.000025 liters of water at 4 ¬∞C. The kilogram is the only SI base unit with an SI prefix as part of its name. It is also the only SI unit that is still directly defined by an artifact rather than a fundamental physical property that can be reproduced in different laboratories. Three other base units in the SI system are defined relative to the kilogram, so its stability is important. The International Prototype Kilogram was commissioned by the General Conference on Weights and Measures under the authority of the Metre Convention, and is in the custody of the International Bureau of Weights and Measures who hold it on behalf of the CGPM.

What measurement type uses [Kilogram] as mass units?