a cap constructed to fit about a jack that includes a port for receiving a plug, spring contacts for making electrical contact with the plug, and insulation displacement contacts housed in an insulation displacement contact housing, the insulation displacement contacts electrically connected to the spring contacts, the insulation displacement contact housing including a top, a back, and two sides, the cap constructed to form a shield structure along at least a portion of the top, the back, and the two sides of the insulation displacement contact housing, the cap including an electrically non-conductive material which is impregnated with an electrically conductive material such that the cap is overall electrically non-conductive, wherein the electrically conductive material of the cap is not constructed to be grounded when the jack is terminated to a cable, wherein the cap includes a notch along the back of the insulation displacement contact housing for allowing a cable to be terminated to the insulation displacement contacts of the jack.