New and high quality. Type to window or door. Ideal entry warning for homes, apartments, mobile homes, offices, hotel rooms,garages and more. Super loud 90 dB alarm. When someone opens the door or window illegally (the relative position of the primary and secondary parts changes), the alarm can issue a strong alarm, warning the intruder to leave and remind the owner. This magnetic sensor can detect the status of your door or window. It can prevent your children from sneaking out and ensure the safety of children, homes, garages, mailboxes and businesses. You can easily install and operate. Press the on/off switch to turn on/off the power, then insert 2pcs AAA batteries (No battery in the box). Tear off the self-adhesive pad on the back of the door alarm sensor, and stick the door handle alarm to the target location. Super environmental suitability and stability. Package Included: 10 x Magnetic Sensor; 10 x Magnetic Stick.