Resistors covered by this specification are intended for use as external resistors for 2.5 inch (63.5 mm) and 3.5 inch (88.9 mm) voltmeters covered by MIL-M-10403 "Meters, Electrical Indicating, Panel Type, Ruggedized, General Specification for", or in other high voltage application for which they may be found suitable. Resistors of the power type, intended to operate at hot spot temperature in excess of 110°C, are not covered by this specification. It is not considered good engineering practice to support these resistors except by their ferrules. Resistors covered by this specification are unique due to the fact that these devices must be able to operate satisfactory in military systems under the following demanding conditions: Undergoes a thermal shock, salt water immersion, vibration, and mechanical strength test. In addition, these military requirements are verified under a qualification system. Commercial components are not designed to withstand these military environmental conditions.