Feature: 1. When the bike security alarm is activated,it is sensitive to any vibrations,protects your bicycle from thefts. 2. 3 adjustable volume levels meet your different demands. 3. 80dB-130dB is loud enough to alert anyone to your presence for safe riding. 4. 3 switchable sensitivity adjustment.When the security alarm is activated,press “+”and “-” buttons to adjust sensitivity level as your needs. 5. Built-in 250mAh rechargeable battery,the horn can stand by for 365 days after fully getting charged. 6. IPX6 waterproof can be used on rainy days. 7. Easily install or release the horn from the handlebar with the rubber straps. 8. Fits for handlebar diameter from 0.86\"(22.2cm) to 1.26\"(32mm). 9. Suitable for mountain bikes, road bikes, electronic bikes, scooters, etc. Specification: Perfect bicycle accessories for you or your kids. Features: When the bike security alarm is activated,it is sensitive to any vibrations,protects your bicycle from thefts. 3 adjustable volume levels meet your different demands. 80dB-130dB is loud enough to alert anyone to your presence for safe riding. 3 switchable sensitivity adjustment.When the security alarm is activated,press “+”and “-” buttons to adjust sensitivity level as your needs. Built-in 250mAh rechargeable battery,the horn can stand by for 365 days after fully getting charged. IPX6 waterproof can be used on rainy days. Easily install or release the horn from the handlebar with the rubber straps. Fits for handlebar diameter from 0.86"(22.2cm) to 1.26"(32mm). Suitable for mountain bikes, road bikes, electronic bikes, scooters, etc. Specification: Color: A / B / C / D / E (optional) Material: ABS + PC Sound: 80dB - 130dB Battery: 1* 250mAh Waterproof level: IPX6 Fits handlebar diameter: 22.2 - 32 mm / 0.86 - 1.26 in Size: 8.67 * 4.33 * 2.21 cm / 3.41 * 1.70 * 0.87 in Weight: approx. 35.2 g / 1.2 oz Package weight: approx. 60 g / 2.1 oz Package List: 1* Electric Horn 1* USB Charging Cable 1* User Manual Package List: 1* Electric Horn 1* USB Charging Cable 1* User Manual