For very low levels of single leakage triaxial & double shielded are used to minimuse this leakage. Triaxial cables are preterred triaxial shielding minimizes 10-20% less Leakage in Comparison to double shield the traixail cable has the usual outer conductor braid. A dielectric layers are provided over it and additional braid is again provided outer Jacket is of PVC in normal course depending upon the attenuation. Stability requirements and frequency.