This Home Security System Entry Kit connects security and convenience through one control hub with remote access and alerts on smart devices. Kit includes 1 control hub with built-in siren and 2 window/door sensors. Build more into the system with compatible ALC SightHD cameras (sold separately). Add up to 4 SightHD cameras and 36 sensors to customize your system. No professional installation required any monthly fees. Easy to set up and use and can be expanded at any time to fit your needs. Full control from your smartphone or tablet.