Periodically, isolation of shields in a coaxial cable is an important consideration. Harbour has constructed a number of TRX (Triaxial) cables, expanding the product line offered in the MIL-DTL-17 specification. (Currently, the MIL-DTL-17 specification defines only one triaxial — M17/131-RG403, a triaxial version of M17/93-RG178.) With an existing double braided construction, an interlayer of insulation is used between the two braids. With a single braided cable, an interlayer and a second braid is used. Complete isolation between the braids is realized, in addition to achieving a more effective shield configuration.