4-in-1 Mode: This alarm offers four distinct modes. 1. Time 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: The alarm stops when the door is closed. 3. Constant Alarm: The alarm sounds continuously, even if the door is closed. 4. Door Opening Chime: Plays a 'Dingdong' sound once when the door is opened. Loud 108dB Alarm: The door and window alarm effectively deters intruders/thieves with a powerful 108dB alarm. Easily select the appropriate mode for your needs. Easy Installation: Simple peel-and-stick installation, easy to apply on most freezers/refrigerators or any door without tools. Package includes 2 refrigerator alarms, 2 magnetic strips, double-sided sticker, and user manual. Installation Note: Ensure the alarm and magnetic strip are aligned. The installation distance between them should not exceed 0.78 inches. The two parts should align using the arrows. 2 AA batteries can last up to 2 years (batteries not included). Widely Used: Magnetic door alarm sensor protects your home at entry points for doors and windows. Suitable for safes, cabinets, freezers, refrigerators, sliding pool doors, shops, offices, apartments, hotels, and more.