Alarm function Combines locking function with alarming function. Built-in movement triggered 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. Can be set to two states: mechanical lock and alarm. Extra batteries. Each lock is pre-fitted with 6 LR44 batteries. You will also get a pack of batteries FREE (6 battery pack). 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 .