BAZHOU Simple, fast and wireless installation: The infrared sensor detects motion and sends a signal to the receiver. Choose from 38 ringtones with bright LED lights. The sensor can be mounted on the wall. Wireless Receiver: Portable wireless receiver plugs into any standard socket. Sensor uses 3 AAA batteries (not included). The detection delay between motion detector alerts can be configured from 15 seconds to 30 seconds by simply placing the sensor at the driveway entrance and placing the receiver in the home. The working range between the receiver and transmitter is up to 100 meters, allowing you to place it further away from the receiver to alert unwanted family members, guests or lawyers or anyone visiting your home or business arrival and departure Perfect for entryways, window frames, sidewalks, sidewalks, and anywhere you'd like to be alerted on movement. Also great for alerting business owners who work from behind or out of sight of customers entering their store. color: White Delivery content: 1x induction welcome doorbell (only the above package contents, no other products) NOTE: Motion detector including plug-in receiver requires 3 AAA batteries (not included). Receiver Dimensions (L x W x H): 80 x 76 x 33 mm. Sensor Dimensions: 80 x 59 x 45mm Have a great time shopping!