Estone Bike Alarm Lock Bicycle Motorbike Moped Cycling Security Sound Loud Anti-theft Traditional chains, padlocks and U Locks only do half a job and can be pretty easily removed by those who know how, but even the sight of this alarm will have even the most determined of thieves thinking twice. If your bike is moved, the alarm will spring into action and give off an ear-shattering shriek for 15 seconds. No thief will want to hang around when this alarm goes off. 3 sensitivity levels allow you to determine how much movement is needed to trigger the alarm. When triggered alarm had already sounded for 5 times, If triggered again within 5 seconds , it will sound continuously for 15 seconds. I'm sure so powerful function must can protect your bicycle effectively. 4 digital code, only the user can unlock. Adopt micro-computer technique. have High-Middle-Lower sensitivity choose. Waterproof: attach permanently to your bike without worrying about having to remove it in bad weather Low power consumption to allow the battery a long life.