1. USB electric speaker with alarm function 2. Built-in 200 mA lithium battery, press 100 times a day, can be used continuously for about 40 days 3. Suitable for a variety of tube diameter bicycle, quick installation and removal 4. One-button switch, switching mode is simple and clear 5. Material: ABS 6. Volume: 120 decibels 7. Battery: 200 mAh 8. Waterproof: IPX-4 9. Net weight: 25g 10. Size: 6.5 x 3.5cm
