Anti-Theft AlarmPress and hold button 3 (lock button) for three seconds to enter the pre-arming state, and ten seconds to enter the anti-theft monitoring state; enter the anti-theft state, with a three-level sensitivity function. Short press button 1 (unlock button) to exit the anti-theft state. (If someone touches or pushes the bicycle, the bicycle alarm will immediately sound a continuous loud siren) IPX6 Waterproof & USB Charging High-quality IPX6 waterproof electric bicycle horn, can be used in rainy days, extremely convenient and practical for daily use; electric bicycle horn alarm adopts USB charging (charging method: charging socket, power bank, laptop.) Simple InstallationEasy to assemble, no tools required, attach the silicone bicycle horn alarm strap to the handle. It can be applied to various bicycles such as mountain bikes / electric scooters / racing cars.