The VTech VC7003 Motion Sensor is an accessory sensor only. It requires a VTech VC71000 IP Hub a VTech ULE Certified Baby Monitor or a VTech VC7151 Wireless Monitoring System with Cordless Telephone to operate. The VC7003 Motion Sensor lets you know when activity is detected so you can stay on top of activity in your home with notifications for everything from visitors approaching to the kids coming and going