3 Alert Options & 38 Chimes to Choose From: You can select 1 of 3 ways of being alerted (Sound/LED Flash/Sound and LED Flash) and 3 volume levels from 25-80dB. You can also select from 38 Ringtones with Bright LED Light. Wireless Plug-in Receiver: The portable wireless plug-in receiver plugs into any standard outlet. The sensor uses 3 AAA batteries (Not Included). Infrared sensor detects motion and sends a signal to the receiver. Detection time delay in between motion sensor 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. Long Distance Wireless: Working range up to 328 feet (100 meters) between receiver and transmitter allowing you to place it a good distance. It can be alerted to visitors, notice door opening, scare off unwanted intruders, or even know when your children have accessed restricted areas. Easy and Fast Installation: This monitor system is fully-expandable, with plug-and-play sensors that can be set up within minutes. The sensors can be mounted to walls, fence posts, trees, or any other surface, for full coverage of your property. Wide Range of Uses: Ideal for front doors, hallway, window frames, driveways, walking paths, and anywhere in your home you want to be alerted to motion. Also great to alert business owners that are working in the back, or out of sight, to customers entering their store.Please note that this not waterproof. Keep it away from rains or cover adequately. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-Dadangjia