Specifications: *Waterproof: attach permanently to your bike without worrying about having to remove it in bad weather *Material: Sturdy black plastic - no metal parts to rust *Fit for: Bicycle *Color: Black *Power supply: 1* 6F22 9V battery (Not include) *Dimensions: 98*60*35mm *Weight: 66g Package Included: -1X Bicycle alarm -4X screws -2X capnut -1X Use Instructio 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.