The RDI-CRE Corrosion Reference Electrode is a professional-grade silver/silver-chloride (Ag/AgCl) reference electrode for performing corrosion potential surveys on boats and yachts. The portable electrode has an integral 20’ marine grade cable and is weighted for easy submergence. Used with a digital multimeter, this simple test is a valuable diagnostic tool to identify stray electrical current and provide warning as to the condition of your vessel’s zincs and drives. The user guide provides an overview of marine corrosion, troubleshooting techniques and corrosion diagnostics for your boat or yacht.