[Security Function (3 volume levels)] - The bike horn (adjustable volume, 80dB-130dB) is loud enough to alert anyone or even people in a vehicle of your presence and ensure your safety while riding. (Press key 2 to open the ring, press key 1 to increase volume, press key 3 to decrease volume). Perfect bike accessory for you or your kids.[Anti-theft (3 levels of sensitivity)] - If someone touches or pushes the bike, the alarm will emit a fast and sustained loud alarm. This bike alarm has a 3-level anti-theft function. Press the key 3 for three seconds to enter the pre-alarm state and press button 1 to close the anti-theft device.[USB Rechargeable and Long Standby Time] - Bicycle horn with USB port for power bank, charging plug and laptop USB. After 1.5 hours full charge, 250mAh capacity can be used for 20-30 days.Easy InstallationEasy to assemble, no tools required, place the silicone bike horn alarm band on the grip. It can be applied to various bikes, such as mountain bikes/electric scooters/racing cars. (Suitable for bicycle handlebars with a diameter of 22.2-31.8mm) Note: The vibration sound in the bicycle bell is a detection of theft sensitivity, which is a normal phenomenon.[IPX6 Waterproof] - This rechargeable bike horn can be attached to mountain bike, road bike, balance bike, electric bike or scooter, which is IPX6 waterproof, can be used in rainy days.Product InformationBike horn with anti-theft functionThe bike horn is a high-decibel 80-130 bell that can automatically adjust volume and has anti-theft alarm function. The bike bell has a jiggling sound, which is used to detect theft sensitivity, what is normal.Fits handlebars with a diameter of 0.86-1.25 (22.2-31.8 mm).Suitable for mountain bikes, road bikes, scooters, electric bikes, children's bikes, motorcycles, etcIPX6 waterproofEven if a storm hits, you don't have to worry about your bike horn getting damaged. It still works.Multifunction button1. Allow ring mode and anti-theft mode.2. Ringer mode: the first button increases the volume, the second button is the default ringtone, and the third button is the volume down. (If you need to honk your horn while driving, you can press any three buttons to make a sound.)3. Anti-theft mode: Press and hold the third button for 3 seconds to switch to anti-theft mode. When put into the state, it has three levels of sensitivity. Long press the first button to anti-theft to unlock.USB chargingThe red light indicates it is charging and the green light indicates it is fully charged.Bike horn with anti-theft alarmThe bike is equipped with an anti-theft alarm function, which can remind others and your own bike that it is in danger and reduce the risk of theft. (try to park the bike within 100 meters of you)Three-level sensitivity in anti-theft stateUnder different sensitivity, sound mode can be adjusted. It can be customized according to your own usage habits.Details on the packaging of the bike hornBicycle bell, USB cable (without charging socket), user manual. Small and lightweight, easy to install.