A planar good electrical conductor part, having a connection lug connects to the outer conductor of a coaxial cable. The part has near its circumference an annular array of through-holes through which contact pins can be passed and brought into contact with the part. A central contact pin can be passed through a recess arranged approximately in the center of the part and can be brought into contact with the inner conductor of the coaxial cable secured to the part by the lug and aligned with the central recess.