locking function with alarming function. Built-in movement triggered the alarm, which can emit loud sounds 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.Low false alarm rate.Low power consumption.Can be used on door, window, bicycle, container, motorbike, tricycle, pull gate, garden, etc.Corrosion-resistant, waterproof, and durable to use. Powered by six button batteries. Supplied with three keys, convenient to use. Note: When you place the shackle with groove into lock near key port, then the lock comes into alarming state.