【Suitable for Various Scenarios】Can be easily mounted using adhesive. Suitable for installation on windows and doors, providing an ideal entry warning for homes, apartments, mobile homes, offices, hotel rooms, garages, and more!.【User-Friendly】Equipped with a magnetic sensor switch that detects the opening and closing of your door or window. Simple stick installation process and operation with a press on/off switch for powering on/off. Insert three button cells (batteries included) and tear the double-sided adhesive located at the back of the alarm to paste on your desired position..【Extremely Loud 95 dB Alarm】 If anyone unlawfully opens a window or door (pertaining to the interchanging primary and secondary components), the alarm can emit a loud warning, urging the intruder to exit and reminding the owner. It also serves to prevent children or infants from wandering outside, securing your residence or workplace regardless of your absence..【High quality】Super suitability and stability. 100% New and high quality.【Package include 】It comes in 3 packs and is environmentally friendly, stable, and dustproof.