The PCWI COIL350 Circular Pipeline Coil Electrode 14" / 350mm Diameter # 0186 CPCE-0186 is ideal for verification of porosity or holidays on pipelines or circular surfaces. This PCWI circular Pipeline Coil is suitable for all High Voltage Porosity detectors, holiday detectors, spark testers and jeepers. The coil electrodes are shipped complete with ball bearing ends.