Easy, Fast And Wireless Installation: The Infrared Sensor Detects Movement And Sends A Signal To The Receiver. Choose From 38 Ringtones With Bright Led Light. The Sensor Can Be Wall Mounted.Wireless Receiver: The Portable Wireless Receiver Plugs Into Any Standard Outlet. The Sensor Uses 3 Aaa Batteries (Not Included). The Detection Delay Between Motion Detector Alerts Is Configurable From 15 Seconds To 30 Seconds, Just Place The Sensor At The Entrance To Your Driveway And The Receiver Inside Your Home.Operating Range Up To 100 Meters Between The Receiver And The Transmitter, Allowing You To Place It A Good Distance From The Receiver To Alert You To The Arrival And Departure Of Unwanted Family Members, Guests Or Lawyers, Or Anyone Who Visits Your Home Or BusinessIdeal For Entryways, Window Frames, Walkways, Walkways, And Anywhere Else You Want To Be Alerted To Movement. Also Ideal For Alerting Business Owners Who Work In The Back Or Out Of Sight To Customers Entering Their Store.Note: Includes 2 Plug-In Receivers And 1 Motion Detector Requiring 3 Aaa Batteries (Not Included). Receiver Dimensions (L X W X H): 80 X 76 X 33 Mm. Sensor Dimensions: 80 X 59 X 45 Mm