country obtained from

• (no filter) 

  Australia (1) Belgium (2) Canada (1) France (1) Germany (1) Netherlands (9) Singapore (1) United Kingdom (3) United States (4)

graduation

• (no filter) 

  deg (14) gon / grad (4) m (1) mil (6400) (1) yard (1)

fine reading

•  direct (analog) (16)
•  drum micrometer (2)
•  scale micrometer (5)
•  scale micrometer (double) (4)
•  vernier (single) (1)

Type of use

•  Military (2)
•  Navigation (1)
•  Survey (17)

Material

•  Aluminium (1)
•  Brass (8)

image direction

• (no filter) 

  inverted (8) upright (12)

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 (20)