Anodes available in Special High Grade (S.H.G.) zinc. The S.H.G. zinc exceeds all industry requirements for chemical composition. Each anode has plated a plated steel core with 14 feet of #12 THHN insulated lead wire attached with silver solder. Packaged anode backfill is composed of 75% Gypsum, 20% Western Bentonite and 5% Sodium Sulphate. Applications include UST, piping, AST bottoms and other carbon steel in contact with the soil. Zinc anodes can be manufactured to your specific requirements.