This KERUI Wireless Security Alarm System Kit is designed for comprehensive home and business security. The main unit supports up to 40 wireless detectors, 10 remote controls, and 10 doorbell buttons, offering extensive expandability. It features a loud siren up to 115dB for effective alerts and includes a PIR motion detector and door/window sensors for complete protection. The system is expandable and can be DIY-configured. It also includes an SOS alarm function via the remote control for emergencies, allowing children and seniors to quickly alert others. The kit is ideal for safeguarding garages, sheds, houses, hotels, and apartments, providing affordable and reliable security.