describe 2 operating modes are available: only the LED indicator flashes or the sound and the LED flash.3-level volume adjustment: high or medium or low.38 ringtones to choose from.The effective working range of the receiver is up to 70 meters.There PIR motion detection distance is 3-7 meters.It can be successfully used in your home, office, store, hotel or other buildings.Ideal for businesses working behind or out of sight when customers enter in the store.It can also be used as a signal when the animal is ready to enter or exit.Applications: entry alarms, intrusion alarms, passage alarms, error detectors, automobile alarms (interior), monitors warehouse security, electrical cabinet alarms, garage and tool shed monitors, mailbox sensors, front door or gateway detection. Package contents: plug-in electronic receiver, PIR motion detector (powered by 3 AAA batteries, not included), wireless electric doorbell kit. Visitor Security Alerts Don't worry, our wireless entrance will never surprise your visitors with alerts again.This wireless infrared motion sensor doorbell alarm is easy to use and set up.Indicators Bright LED and a choice of 38 ringtones allow you to personalize your alerts. installation steps: 1.Insert the correct battery (3 AAA batteries) (not included) into the sensor, making sure the battery is in the correct place. 2.Properly install the sensor on the front door, window frame, driveway, sidewalk, garden or wherever you need it. 3. Turn on the receiver and adjust the volume to the correct position. 4.Now the remote sensing system adopts infrared detection technology. 5.Place the receiver in an easily accessible location. 6.When the sensor detects movement, the receiver will emit a sound and the LED indicator will flash. 7.Please wait 30 seconds after turning on the sensor and receiver to activate it. Size: Receiver size: 76*80*33mm Transmitter size: 80*59*45mm Quantity delivered: 1 piece doorbell