4 in 1 Mode: This alarm features 4 modes. 1. Timing alarm (emits a 'Di-Di-Di' sound increasing 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 (continues sounding even after the door is closed); 4. Door opening chime (emits a single 'Ding-Dong' when the door is opened). Loud 108dB Alarm: This door and window alarm helps effectively deter intruders or thieves with a loud 108 dB alert. You can easily select the appropriate mode based on your needs. Easy to Install: Simple peel-and-stick setup allows for quick installation on most freezers, refrigerators, or any door without the need for tools. Package includes 2 fridge alarms, 2 magnetic strips, double-sided adhesive tape, and a user manual. Electronic instructions are shown in the eighth image. Installation Note: Ensure the alarm and magnetic strip are properly closed. The installation distance between the two parts should not exceed 0.78 inches. The alignment arrows on both parts must be matched. Operates on 2 AA batteries, which can last up to 2 years. (Batteries not included). Widely Used: Magnetic trigger door alarm sensor provides protection for home entry points including doors and windows. Suitable for use on safes, cabinets, freezers, refrigerators, sliding doors, shops, offices, apartments, hotels, and more.