MIL-C-172C, MILITARY SPECIFICATION: CASES; BASES, MOUNTING; AND MOUNTS, VIBRATION (FOR USE WITH ELECTRONIC EQUIPMENT IN AIRCRAFT) (08 DEC 1958)., This specification covers cases, mounting bases, and vibration mounts used to enclose and isolate electronic equipment in aircraft from external vibrations. This specification establishes the general requirements and dimensions therof, defines the space limitations in aircraft therefor, and sets forth the performance and dimensional requirements thereof, in order to insure interchangeability.