The fiber optic connectors covered by this specification are intended for use in military applications where their performance characteristics are required. The connectors covered by this specification are unique due to the fact that these items must be able to operate satisfactorily in systems under the following demanding conditions: 10 g's vibration, over 1,000 g's of shock, temperature excursions from -40 to +158 °F (-40 to +70 °C), and mechanically harsh conditions. For applications with vibration exposures greater than 75 Hz, lock wire and connector coupling torques higher than those specified in table III should be considered. A gasket is not provided with receptacles, and a gasket may be required to achieve shielding effectiveness specified herein. For applications using dummy termini, lock wire and connector coupling torques higher than those specified in table III should be considered. In addition, these requirements are verified under a qualification system. Commercial connectors are not designed to withstand these environmental conditions.