4 in 1 Mode: This alarm with 4 modes. 1.Timing alarm (sounds "Di-Di-Di" from 0dB to 108dB if door stay open for 3/15/30/60s) 2.General alarm (alarm stop if door closed); 3.Constant alarm (constant alarm even closed door); 4.Door opening chime (sounds DingDong once the door is opened) Loud 108dB alarm: Door and window alarm helps effectively deter intruders/ thieves with a loud 108 dB alarm. You can easily set the suitable mode according to your needs. 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. The electronic instruction is on the eighth picture. Note on installation: 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) Widely Used: Magnetic Trigger Door Alarm Sensor Protecting Home Through Door Window Entrance and Suitable for Safe, Cabinet, Freezers , refrigerators, swimming pool sliding door, shop, office, apartment, hotel, etc. About shlpping: All items will be shlpped within 3 business days after the payment is received. Most times you will receive them within 8-12 days then. The specific delivery time is depend on circumstances.Any questions, please feel free to contact us During the shopping process, if you have any questions, please feel free to consult us, we will reply you within 24 hours, wish you a happy shopping Thanks for your cooperation and we'll make you feel satisfied.