4 in 1 Mode: This alarm has 4 modes. 1. Timing alarm (if the door is kept open for 3/15/30/60 seconds, it will sound "Di-Di-Di" from 0dB to 108dB) 2. General alarm (if the door is closed, the alarm stops);3 .Continuous alarm (even when the door is closed); 4. Loud 108dB alarm for door opening chime (jingling after opening the door): Door and window alarms help to effectively deter intruders/thieves with a loud 108dB alarm. You can easily set a suitable mode according to your needs. EASY TO INSTALL: Simple peel and stick installation, easy to install on most freezers/refrigerators or any door without any tools. The package includes 2 refrigerator alarms, 2 magnetic strips, double-sided stickers, user manual. Electronic instructions are on the eighth picture. Installation Notes: Be sure to turn off the alarm and the magnetic strip, and the installation distance between them should not exceed 0.78 inches. The two parts must be aligned by their alignment arrows. 2 AA batteries can be stored for 2 years. (Battery not included) Wide range of applications: Magnetic trigger door alarm sensor protects home through door and window entrances, suitable for safes, cabinets, freezers, refrigerators, swimming pool sliding doors, shops, offices, apartments, hotels, etc.