When sourcing MI cables, you must prioritize the sheath material, conductor type, and insulation quality. Common sheath materials include Stainless Steel (304, 316L, 321) for general corrosion resistance and Incoloy 825 for high-temperature or acidic environments. Ensure the insulation is high-purity Magnesium Oxide (MgO), which provides superior electrical insulation and thermal conductivity. The maximum withstand temperature is a critical metric; high-end MI cables can operate continuously at temperatures up to 600°C to 800°C.