country obtained from

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  Australia (1) Belgium (2) Canada (1) France (1) Germany (1) Netherlands (10) Singapore (1) United Kingdom (4) United States (11)

graduation

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  cables (1) deg (15) ft (1) gon / grad (4) m (1) mil (6400) (2) yard (8)

fine reading

•  direct (analog) (25)
•  drum micrometer (2)
•  scale micrometer (5)
•  scale micrometer (double) (4)
•  vernier (double) (1)
•  vernier (single) (1)

Type of use

•  Military (6)
•  Navigation (6)
•  Survey (18)

Material

•  Aluminium (3)
•  Brass (15)
•  Plastic (1)

image direction

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  inverted (9) upright (18)

Brand

•  Ajax Engineering Co. (1)
•  E.R. Watts and Son (1)
•  Henry Hughes and Son (1)
•  JH Steward (1)
•  Keuffel and Esser (1)
•  Schick (3)
•  US Naval Gun Factory (1)
•  Western Electric (1)
•  Wild Heerbrugg (22)