TECKNET Door Alarms for Kids Safety, Door Alarms When Opened, Two-Way Door and Window Alarm Door Alarm for Home Security, 2-in-1 Alarm & Chime, 3-Level Volume Control, Door Sensor Alarm (3 Pack)

【Quick alarm】 When the distance between the alarm and the magnetic sensor exceeds 0.78 inches, the door and window alarm will sound an alarm. (Low-voltage alarm: when a short DIDI sound sounds after the alarm, it means that the battery is low and needs to be replaced in time.)
【Five Alarm Modes】By short pressing to adjust the alarm mode, there are five modes to switch according to the situation: 1. Alarm when opening the door, and stop when closing the door; 2. Ding-Ding doorbell alarm; 3. Alarm after opening the door lasts for 30S; DIDI alarm when opening the door, and stop when closing the door; 5. Alarm after opening the door for 15S, and last for 30S.
【3-Level Volume Control】This window alarm sensor has 3-level volume control, which is an ideal choice for apartments, mobile homes, offices, hotels, garages and other places. Press and hold the SET key to adjust the volume. There are three levels of volume adjustment to meet your alarm and reminder needs.(Built-in 3 × LR44 batteries)