Xiaomi Smart Band 9 Active is a budget-friendly fitness tracker featuring a 1.47-inch TFT display with a 60Hz refresh rate, up to 18-21 days of battery life, and a 9.99mm slim, 16.5g lightweight design. It supports 50 sports modes, 5ATM water resistance, and comprehensive health monitoring, including 24-hour heart rate, SpO2, sleep, and stress tracking.