WUZHOU User-Friendly: There are 2 modes choices (LED Flash/Sound and LED Flash), 3 levels volume adjustment (High/Middle/Low ) and Ringtones to choose. Effective Distance: Working Range between receiver and transmitter allowing you to place it a good distance from the receiver to warn you of arrival and departure of family members, unwanted guests or solicitors, or anyone who visits your home or business. Wireless Plug-in Receiver: The portable wireless plug-in receiver plugs into any standard outlet. The sensor uses 3 AAA batteries. 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. Applications: Ideal for front doors, 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. Easy Installation: As for this visitor chime, there are no wires to run, no installation hassles, the sensor is wall mountable. You just need to put in the batteries, and place the wireless motion sensor and alarm receiver wherever you prefer. Delivery Quantity: 1set (2pcs) Package Contents: Only the above package contents, excluding other products. Batteries are not provided. Size: Details as shown (Reminder: The size is measured manually, please allow 1-2 cm measurement error) color: White (Due to different monitors and lighting effects, the actual color of the item may be slightly different from the color shown on the picture.)