Regency Wire 26980306 500'/RL #18 Blue Solid Tracer Wire. Suitable for direct burial to facilitate the detection and tracing of underground utility systems. Tracer Wire is a solid copper conductor insulated with a linear low density polythylene (LLDPE), classified as high molecular weight polythylene (HMPE). Insulation provides excellent abrasion, crush, chemical, oil and moisture resistance. A single conductor tracer wire is intended to carry a radio signal to aid in the location of buried utility lines. The wire may be identified by surface printing, indicating manufacturer, conductor size. Custom Legends available. UL listed.