Adjustable Volume & Security System for Your Home130 DB Siren alarm can not only cause a huge shock to thieves, but also wake you up in your sleep to prevent a horrible accident. A door and window alarm with wide applications, break-in warning, ideal for home, office, hotel, apartments, garages, dorm room, or even RV. Effective and Responsive & Keep Your Kids SafeThe door alarm is activated when the door opens more than 15MM. This alarm is powerful enough to detect entry, it lets you know when your children open doors or windows to prevent children and babies from going out, whether you are inside or outside the house. Especially, if you have a swimming pool at home, it is very necessary to install a door alarm. 5 Alarm ModesThis door/window alarm has 5 modes for alarm or daily use: (1) Door open alarm, door closed stop mode (2) Doorbell mode (3) 30 seconds continuous alarm mode (4) DiDiDi mode (5) Delayed alarm - door not closed reminder mode. You can change the alarm mode by pressing the "SET" button according to your needs. Simple Operation with Batteries Included Shackcom door and window alarm works with a set of 3 LR44 button batteries, for each alarm, there are 3 LR44 button batteries inside the product, moreover, we give 10 extra batteries. When the alarm is weak, you need to replace the batteries to better protect your home.