1. Four Modes After the wireless fridge alarm has been turned off for a relatively long time, close the door or bring the magnetic strip near the main unit. After a 15 second startup, you can switch between the four functions by turning the power switch multiple times, and you will hear four prompt sounds. Switching once is the alarm mode; twice is the continuous alarm mode; three times is the door closing reminder mode; and four times is the doorbell mode. 2. Easy to Install: The fridge alarm can be easily installed on any refrigerator, freezer, or door using adhesive tape. Note: For performance, ensure the distance between the alarm sensor and the magnet does not exceed 2.3 cm. 3. Reliable Intrusion Alert: This door and window alarm is designed to immediately detect when a door or window is opened. With a powerful 110 dB alarm and a reliable magnetic sensor, it effectively deters unauthorized entry and enhances your home security in any environment. 4. Low Battery Warning: When the battery power is low, the half door alarm will sound briefly to prompt a battery replacement. It can last for about a year. A battery is included as a gift and can be used immediately upon receipt.