120DB: Security door alarm with 120DB to detect entry, prevent children and babies from leaving the house, protecting the safety of your home or office. Simple Installation: Ultra-thin door and window alarm, can be easily installed on any door or window, which will not damage your furniture. High Accuracy: The doorbell alarm is suitable for children sleeping alone, the elderly and pregnant women, with high accuracy and no false alarm. Easy Operation: When opening the door, the main machine will emit a 120 DB alarm sound. When the door is closed, the alarm sound will stop. Low Voltage Warning: You will easily know when to replace the batteries with the low battery indicator of the door alarm, no worry about not working.