SadoTech Hands-Free Door Chime or Window Alert with Magnetic Sensors, Activates When Door or Window is Opened, Door Open Chime or Window Alert, 2 Mini Discrete Door Sensors + 1 Plug-in Receiver

* [HANDS FREE ALERT ACTIVATION] Operates as a door or window sensor. Works using a reed switch and a magnet. The reed switch attaches to your window or door frame, and the magnet attaches to the window/door itself. When a window/door with an active sensor is opened, the magnet pulls away from the reed switch and the alert chime is triggered. * [LONG RANGE EXPANDABLE SYSTEM] This wireless open sensor alarm system for home has a long operating range of up to 1000 ft and ensures that you will never miss a visitor no matter where you are in the house. You can also EASILY ADD on 20+ more extra receivers, transmitter buttons, motion sensors and door sensors. Custom build your own door alarms for home to fit your needs. For homes, apartments, basements, warehouses, offices, garages, and more! * [EASY INSTALLATION] Just plug the doorbell receiver into any electrical outlet and strip off the double-sided adhesive tape that is on the back of the door sensor and attach it to the door or window. All hardware is includ...