Alarm function Combines locking function with alarming function. The built-in movement triggered an alarm, which can emit loud sound when the lock is hit or shaken. Adopts MCU core procedures, high-tech integrated circuit, and digital sensor chip. It can be set to two states: mechanical lock and alarm. Each lock is pre-fitted with 6 LR44 batteries. This lock can be used as an Ordinary. Alarmed by simply taking out the shackle and inserting it back into the lock the other way round. When the lock is Alarmed a single Bleep will be heard. Once armed it has a unique program that controls the sensitivity, this is very important, as you don't want it going off all the time when it is windy, our locks are designed with a unique microchip that controls the sensitivity, There are similar looking products on the market but none that have this technology built-in. The lock has three sensitivity levels LOW-MED-HIGH.