4-in-1 ModeOur Loud Door And Window Open Alarm have four modes for your convenience, so you can easily and conveniently set the appropriate mode as your need. Wide Range of UsesThis Doorbell Ringer Wireless Alarm ideal entry warning for homes, apartments, mobile homes, offices, hotel rooms, garages, and more. Anti-theftOur Loud Door And Window Open Alarm detects your door or window. When someone opens the door or window illegally, the alarm can issue a strong alarm, warning the theft to leave and reminding the owner. Easy to UseThis Doorbell Ringer Wireless Alarm emits a low volume beep when you exceed the allowed gap between the Alarm and the mini sensor, open/close the door to check before peeling the double-sided tape. Low Battery IndicatorUse This Refrigerator Door Alarm, you will easily know when to replace the batteries with its low battery indicator and replace the battery in time to ensure that the equipment works normally. Descriptions: 1It's the ideal protector from unwanted intruders, whether you're inside or out. 2Easy installation with tape, just peel and stick to windows, doors, cabinets or tool boxes, etc. 3Electronic magnetic sensor switches detect input and protect your home, office, apartment, hotel room, garage, and more, whether you're in or out. 4Portable enough to take with you on business trips and vacations, keeping you and your home safe and secure. 5Test the setup by opening the system to see if the alarm can be triggered by opening the door/window. Properties: Material: PP Size: 3.3*1.7*0.6 inches Power supply mode: AAA battery*2 (not included) Working environment temperature: -10~60C/14~140F Product List: 1* Home Door Security Alarm Notice: When the door sensor is activated, the sensor will sound an alarm. And it can be installed on the window to prevent children from accidentally opening it.