MIL-B-81705C, MILITARY SPECIFICATION: BARRIER MATERIALS, FLEXIBLE, ELECTROSTATIC PROTECTIVE, HEAT-SEALABLE (25 JAN 1989) [S/S BY MIL-PRF-81705D]., This specification establishes the requirements for heat-sealable, electrostatic protective, flexible barrier materials used for the military packaging of microcircuits, sensitive semiconductor devices, sensitive resistors, and associated higher assemblies. In addition, the type I materials provide for watervaporproof protection and attenuation of electromagnetic radiation (see 6.1).