MIL-B-45852 Revision A, September 29, 1965
BORESCOPES M1 AND M2
Includes all amendments and changes through Validation Notice 2, October 25, 2013
Additional Comments: INACTIVE FOR NEW DESIGN
This specification covers two sizes of borescopes for inspecting bores 20MM and over.
Borescopes covered by this specification shall be of the following types:
a. M1 - for bores of 20-57MM
b. M2 - for bores over 57MM