"Freezer Door Alarm Warning: They can function as a refrigerator door alarm. If your refrigerator door is opened by children, it will sound DiDiDi to remind you until the door is closed. (Set Mode 4). Refrigerator Door Alarm: Triggered if the refrigerator or freezer door is open for 15 seconds. It will only alert you when the freezer or refrigerator door has been open for 15 seconds. (Set Mode 5) Multi 5-in-1 Mode Alarm: Intrusion Alarm (Door alarm for child safety) Doorbell Sounds Dingdong like a magnetic doorbell when the door is opened for business Continuous Alarm (Door alarm for 30 seconds even if the door is closed) Di Di Sensor Alarm (Sounds Di di di. a good refrigerator alarm for children) Refrigerator Door Alarm with 15-second delay (like a refrigerator door alarm when left open, it starts after 15 seconds and stops after 30 seconds). 3 levels of adjustable volume from 80dB to 130dB. : The magnetic sensor door/window alarm is loud enough to be noticed. It can not only be used to protect your home security, prevent children from leaving the house without notice, but also can be used to remind you that doors/windows/medicine cabinets, refrigerators, or freezer doors are not closed. Portable & Easy to Install: Use double-sided tape, stick it on the refrigerator door or wherever you need it, then everything is ready! No wires or screws needed. Suitable for home, office, apartment, garage, pool gate, medicine cabinet, refrigerator, freezer, etc. Also for travel. Instant Alarm Reminder: The minimum trigger distance is 0.59 inches. The alarm will be triggered and alarm immediately when doors or windows are opened. Double-sided Magnetic Sensor Alarm: More locations can use it than a single-sided sensor. This product does not contain batteries.