The heating plate at the bottom of Mi Smart Kettle Pro is made of national standard 06Cr19Ni10 (stainless steel 304) material, which has excellent anti-rust effect and can fully meet the normal use conditions of the kettle. The cause of small rust spots may be that other substances in the water react with stainless steel. Rust can be cleaned as follows: 1. Most of the time, the small spots are scale. If you find yellow spots, pitting spots, rust spots, etc., you can try to clean them with citric acid or edible vinegar. 2. If the above cleaning is invalid, you can clean them. Try to clean it with sandpaper or white cloth; 3. A small amount of rust is often accompanied in our life and will not affect human health.