HSK 6 HSK V4
Correct

毫米

/ háomǐ / 
Strokes
https://i.cchatty2.com/filters:format(webp)/fit-in/684x0/img/202005/毫米-Chinese-words-Cchatty-yyyy-1589851706.jpg

Definition

millimeter

Example

毫米 Nominal measure words —— Measure units
As a Measure word
millimetre (mm)