Zinc-Aluminum-Magnesium Cable Tray refers to a cable management system that uses a unique alloy coating consisting of zinc, aluminum, and magnesium. With its enhanced corrosion resistance, high strength, and lightweight properties, this. Our market-leading cable tray system is now available in ZM (Zinc Magnesium), as well as existing finishes (pre-galvanized, hot-dip galvanized, powder coated and stainless steel). The unique composition offers excellent corrosion protection which is equal to Hot Dipped (aka Post) Galvanized steel, as well as several additional benefits. And like all our stock items, they're available for rapid delivery to ensure zero project delays. What is Zinc Magnesium? We've sung.