Thước cặp

1 - Outside jaws: used to take external measures of objects
2 - Inside jaws: used to take internal measures of objects
3 - Depth probe: used to measure the depth of objects
4 - Main scale (cm)
5 - Main scale (inch)
6 - Vernier (cm)
7 - Vernier (inch)
8 - Retainer: used to block movable

( Liễu Ngân Đình - www.meslab.org/mes )