1. Bluetooth version: 5.1 2. Bluetooth distance: 15m (no interference) 3. Turn on the light and use time: about 8 hours 4. Turn off the light and use time: about 20 hours 5. Horn size: 40 mm in diameter 6. Battery capacity: 400mAh 7. Adjustable hair band, suitable for people of different ages. 8. Foldable and portable design, easy to store.