4 in 1 Mode: This alarm features 4 modes. 1. Timing alarm (emits 'Di-Di-Di' sound from 0dB to 108dB if door remains open for 3/15/30/60 seconds) 2. General alarm (alarm stops when door is closed); 3. Constant alarm (continues sounding even after door is closed); 4. Door opening chime (produces a single 'Ding-Dong' sound when door is opened). Loud 108dB Alarm: The door and window alarm effectively deters intruders with a powerful 108 dB alert. Easily select the appropriate mode based on your requirements. 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 inch. Align both parts using their alignment arrows. Operates on 2 AA batteries (not included), which can last up to 2 years. Widely Used: Magnetic trigger door alarm sensor provides security at entry points such as doors and windows. Suitable for use on safes, cabinets, freezers, refrigerators, sliding doors, shops, offices, apartments, hotels, and more.