country obtained from

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  Belgium (2) Netherlands (6) Singapore (1) United Kingdom (1) United States (7)

graduation

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  cables (1) deg (8) gon / grad (3) m (1) yard (5)

fine reading

•  direct (analog) (15)
•  drum micrometer (1)
•  scale micrometer (2)
•  scale micrometer (double) (1)
•  vernier (double) (1)
•  vernier (single) (1)

Type of use

•  Military (3)
•  Navigation (4)
•  Survey (11)

Material

•  Aluminium (3)
•  Brass (5)
•  Steel (1)

image direction

• upright (18) 

  inverted (11)

Brand

•  Ajax Engineering Co. (1)
•  Henry Hughes and Son (1)
•  Schick (2)
•  US Naval Gun Factory (1)
•  Western Electric (1)
•  Wild Heerbrugg (12)