dual wall (insulating/semi-condutive) tubing is co extruded to improve electrical performance, reduces ... /3085305.01000mmDWST-φ100/38100385.51000mmDWST-φ120/45120455.51000mmdual wall (insulating/semi-condutive) tubing is co extruded to improve electrical performance, reduces ... tubes used within a joint, making it more user friendly. semi-conductive/insulation double layer sleeve