4 in 1 Mode: This alarm with 4 modes. 1. Timing alarm (sounds Di-Di-Di from 0dB to 108dB if the door remains open for 3/15/30/60s) 2. General alarm (alarm stop if door closed); 3. Constant alarm (constant alarm even door closed); 4. Door opening chime (sounds inchDingDonginch when door is opened)<br> Loud 108dB alarm: Door and window alarm helps effectively deter intruders/thieves with a loud 108dB alarm . You can easily set the suitable mode according to your needs.<br> Easy to Install: Simple peel and stick installation, easy to install on most freezer/refrigerator or any door without any tools. package including 2 fridge alarms, 2 magnetic strips, double-sided sticker, user manual. <br> Installation Note: Be sure to close the alarm and the magnetic strip, the installation distance between them should not exceed 0.78 inch. The 2 parts must be aligned by their alignment arrow. 2 AA batteries can stay for 2 years. (batteries are not included)<br> Widely Used: Magnetic trigger door alarm sensor protecting home through door window entrance and suitable for safe, cabinet, freezers, refrigerators, door slider for swimming pool, store, office, apartment, hotel, etc.<br> Number of pieces : 2<br> When shopping, please pay attention to the size and dimensions of the product to ensure that it meets your needs. In the title and , we have provided detailed information about the product, including its features and specifications<br>