Features:100% brand new and high quality4 digital code, only the user can unlock.Adopt micro-computer technique , have High - Middle-Lower sensitivity choose.Quiver trigged, security and sensitivity .Low power consumption to allow the battery a long life .Easy to installation and DIYAfter parking the bicycles, press "B" for 2 seconds, you will hear 1 beep if successful and it will armed 5 seconds after the beep.When triggered the alarm will sound 5 times and if it is triggered again within 5 seconds it will sound for 15 seconds continuously.Specifications:Color: BlackPower: 6F22 9 V battery * 1(not include)Alarm decibel : more than 105dbPackage includes:1 x Bicycle alarm lock