The PCWI COIL1010 Circular Pipeline Coil Electrode 40" / 1010mm Diameter 0199 CPCE-0199 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.