4 in 1 Mode: This alarm with 4 modes. 1. Time-Delay Alarm (sounds 'Di-Di-Di' from 0dB to 108dB if the door is left open for 3/15/30/60s); 2. General Alarm (alarm stops if the door is closed); 3. Constant Alarm (alarms constantly even when the door is closed); 4. Door-Opening Chime (sounds 'DingDong' once the door is opened) 108dB Loud Alarm: The door and window alarm helps effectively deter intruders/thieves with a 108dB loud alarm. You can easily set the appropriate 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. Package including 2 refrigerator alarms, 2 magnetic strips, double-sided sticker, user manual. Installation Note: Make sure to close the alarm and the magnetic strip, the installation distance between them should not exceed 0.78 inches. The 2 parts should be aligned by their alignment arrow. 2 AA batteries can stay 2 years. (batteries are not included) Widely