Door/window alarm battery-operated | 2x CR2032 | 85 dB | White This ultra-thin glass break detector has an integrated window/door alarm that is activated when the window or door pane breaks or the door/window is opened. You can use the switches on the side of the alarm to switch it on and off as required and adjust the detection sensitivity. The thin profile is ideal for mounting on a window or door. The alarm requires 2 x CR2032 batteries (included) with an average lifespan of one year. The alarm gives an indication when the batteries are running low and you can press the "battery test" button at any time to check the status of your batteries. No tools are required for the alarm device: it has magnetic sensors and is equipped with double-sided adhesive tape (included). Stick the alarm device on the glass of the door or window and place the magnetic sensors on the door or frame and you're done.