JisuLife FA31 USB Rechargeable Hanging Neck Mini Fan Bladeless Cooling Outdoor High Wind Power Electric Fan(Mint Green)1. Battery capacity: 4500mAh 2. Use time: about 3. 5 21. 5h 3. Charging port: Type C 4. Wind speed: 4 speeds 5. Size: about 18. 25 x 21. 8 x 7cm 6. Weight: about 279g Features: 1. Pressurized air chamber to reduce noise and increase airflow from the air ducts 2. neck diamond pattern silicone pad design, reduce the contact area and moisture and sweat adhesion 3. Circulating airflow gain technology, so that the back of the neck is full of cool air 4.