GRSICO HOME SECURITY SYSTEM: The great home alarm system includes 1 Wi-Fi Gateway and 4 door/window sensors. Only work on 2.4GHz WiFi. (NOT SUPPORT 5G) | Easily DIY Installation: Set up the alarm system in minutes all do it yourself making home security easier. Just need to attach the contact sensors to door/window. | No Alarm Sound: When a sensor is triggered, you'll get an alarm alert from the mobile app, and by renaming it you'll know where it was opened. The gateway and door/window sensor won't make any annoying noise, and there will be no false alarm sound to disturb your sleep at night. | App Control: Wherever you are, you can control and monitor your home security system on the AGSHOME App anytime, such as arm/disarm your home remotely, and personalized Entry, and Exit Delay. A great way to get started in whole-home protection for your home security. | Early-Warning Notifications: Receive real-time early-warning notifications in the form of smartphone banner alerts, limited SMS/text messages, and calls(add-on values) to deter burglars successfully and always give you peace of mind. | Easily Expandable: Supports up to 20 sensors and 5 remotes. Add additional entry sensors, motion sensors, keypads, remotes, and more to GRSICO alarm system to quickly and easily expand your entire home security to suit the size and layout of your home. | No Contract Fee: Free app alerts, no need to pay any subscription service fees, GRSICO Wi-Fi home security system 24-hour comprehensive protection of your family's safety.