Welcome to our store!</br>1、Wide Uses: Extensively used in homes, offices, hotels, shopping malls, cabinets, windows, etc., very well to meet your various needs. 2、Easy to Install: Just use double sided tape (not included) to install the sensor on the door and window frame, no need complicated installation tools. 3、Principle: When the distance between the magnetic block and the strip is more than 7mm, an alarm sound of 105db will be emitted. 4、Built‑in Battery: Built‑in three 1.5V 150mah LR44 button batteries with long battery life, no need to replace battery frequently. 5、High Performance: The door window burglar alarm is very sensitive, effectively protecting your safety. <p class="wang-edit-text"><p class="wang-edit-text"> Item Type: Door Window Sensor Material: ABS Application: For home, office, hotel, shopping mall, etc. Battery: Built-in 3pcs LR44 button battery 1.5V, 150mah Alarm Volume: 105dB Alarm Distance: Approx. &gt;7mm/0.3in <style> .wang-edit-text{ font-family:'Arial' !important; } .wang-edit-text table { border-top: 1px solid #000; border-left: 1px solid #000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid #000; border-right: 1px solid #000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; }</style> 1 x Alarm Host 1 x Magnetic Strip (Customer Satisfaction) - is our priority. If you notice any problems with the products after receiving the goods, such as damaged goods or incorrect quantity, please contact us immediately. We will do our best to provide you with satisfactory after-sale service.</br>