hi what is a millimeter
The millimeter (British English: millimetre; abbr. mm) is a metric length unit, which is equal to 1/10 centimeter and 1000 micrometers. One international inch has 25.4 millimeters. The inch (abbr. in, symbol â) is a non-metric length unit in various systems. There are 25.4 millimeters in one international inch.