1. The motor can be upgraded to 500W: +20usd; The motor can be upgraded to 800W: +40usd 2. The power switch can be equipped with a key + 20usd 3. The folding buckle process can be replaced for free 4. The tire can be upgraded to a run-flat tire + 20usd 5.Add mirror + 10usd/ pair 6. The battery can be upgraded to a high-quality battery + 20usd