4 in 1 Mode: This alarm features 4 modes. 1. Timing alarm (emits a 'Di-Di-Di' sound from 0dB to 108dB if the door remains open for 3/15/30/60 seconds) 2. General alarm (alarm stops when the door is closed); 3. Constant alarm (alarm continues even after the door is closed); 4. Door opening chime (emits a single 'Ding-Dong' when the door is opened). Loud 108dB Alarm: The door and window alarm effectively deters intruders with a loud 108 dB sound. Easily select the appropriate mode based on your needs. Easy to Install: Simple peel-and-stick setup allows quick installation on most freezers, refrigerators, or doors without tools. Package includes 2 fridge alarms, 2 magnetic strips, double-sided adhesive tape, and user manual. Electronic instructions are shown in the eighth image. Installation Note: Ensure the alarm and magnetic strip are properly closed. The distance between them should not exceed 0.78 inches. Both parts must be aligned using the alignment arrows. Uses 2 AA batteries (not included), which can last up to 2 years. Widely Used: Magnetic trigger door alarm sensor provides security for home entry points including doors and windows. Suitable for safes, cabinets, freezers, refrigerators, sliding pool doors, shops, offices, apartments, hotels, and more.