The only lock with built-in alarm and shock sensor! Made from Hardened Zinc Alloy Body, this alarm lock protects you from unnecessary losses. The alarm lock is designed to withstand rough weather and resistant. What makes this lock outstanding is the alarm feature, which can be turn ON/OFF by just switching the shackle arm. When the alarm is turned on, once it is triggered by external force or any movement, the lock will beep once as a sign of warning, if the lock is triggered once again, the alarm of the lock will be triggered and it will produce a 110db loud alarm siren, which is average human eardrum pain threshold. The alarm can be turned off immediately by opening up the lock.