A unit of length: millimetres, centimetres, metres or inches. Model units carry no unit of
their own; this names the one they are in where a file, a standard's sizes or a conversion
needs to know it. The values are the short codes design documents and assembly structures use.
A unit of length: millimetres, centimetres, metres or inches. Model units carry no unit of their own; this names the one they are in where a file, a standard's sizes or a conversion needs to know it. The values are the short codes design documents and assembly structures use.