4-in-1 Mode: This alarm with 4 modes. 1. Time Delay Alarm (sounds "Di-Di-Di" from 0 dB to 108 dB when the door remains open for 3/15/30/60 seconds) 2. General Alarm (alarm stops when the door is closed); 3. Constant Alarm (continuous alarm even when the door is closed); 4. Door Opener Beep (sounds "DingDong" once the door is opened) 108 dB Loud Alarm: The door and window alarm effectively deters intruders/thieves with a loud alarm of 108 dB. You can easily set the appropriate mode according to your needs. Easy Installation: Simple peel-and-stick installation, easy to install on most freezers/refrigerators or any door without tools. Package includes 2 refrigerator alarms, 2 magnetic strips, a double-sided sticker, and an instruction manual. Installation Note: Make sure to close the alarm and the magnetic strip. The installation distance between them should not exceed 0.78 inches. The two parts must be aligned according to their alignment arrow. 2 AA batteries can last for 2 years.