INTELLIGENT POSTURE REMINDER: This posture corrector features the latest inductive design. When your back bends beyond 25 degrees, the device automatically senses the movement and activates a vibration alert. If your shoulders slouch forward or muscle tension becomes abnormal, the sensor will vibrate immediately to remind you to adjust your posture.LONG STANDBY TIME: The back corrector is equipped with a 500mAh polymer lithium battery. After 2 hours of charging, it can be used for approximately 15 days. Charging is simple using the included USB cable. The power switch has an indicator light: a steady red light indicates charging, while a steady blue light indicates a full charge or normal operation. If the device does not turn on, please charge it for at least 10 minutes before use.HIGH-ELASTIC NYLON BELT: The adjustable shoulder straps are made of high-elasticity nylon with a breathable mesh design, offering enhanced comfort and airflow to prevent overheating. The soft, non-restrictive fit ensures all-day wearability without digging into the armpits or causing skin irritation. Suitable for users weighing between 15 kg and 95 kg.SCIENTIFIC AND EFFICIENT CORRECTION: For best results, we recommend wearing the posture corrector for 2 hours per day. Wearing it consistently for 21 days helps form healthy posture habits, with significant improvement expected over 90 days of regular use. This device supports long-term muscle memory development for better posture. If the vibration function does not activate properly, please refer to the user instructions.Specifications: Battery capacity: 500mAh / 3.7V Power supply: 5V Power consumption: 0.4W Charging time: about 2 hours Charging voltage: 5V Net weight: 85g Material: ABS + elastic nylon belt Charging interface: standard V8 USB port This brand offers reliable products and provides 24-hour customer support. If you have any questions or concerns, feel free to were always here to help.