A tool string composite transmission element comprising a composite polymeric carrier comprising an electrical conductor embedded therein. The conductor may be connected to ground and to a cable and may be suitable for producing an electromagnetic field within the carrier when energized. The conductor may comprise a tab that may align with a slot within the carrier to prevent rotation of individual carrier fragments or segments strung along the conductor. The carrier may comprise a volume of MCEI particles sufficient to allow the carrier to transmit the electromagnet field to an adjacent carrier. The transmitted field may be used to convey data and power. The carrier may comprise an annular or linear configuration. Also, the carrier may comprise a bumper for securing the carrier within a groove within a tool within the tool string. The carrier may comprise a depression in its outer top surface above the electrical conductor.