Motion sensor distance: The detection distance of the infrared device is 2-8 meters. The remote control distance in the open area is up to 280 meters, which can meet the needs of multiple locations. [Entry Alert] Home or business owners can use the doorbell to be alerted when people enter or leave. Use it to detect visitors through the front or back door. The portable design is easy to install in homes, offices, stores and can also be used for mailboxes, garages, entryways and more. [Reduce errors] Using ASK Superheterodyne with the same frequency and different code technology, the error rate is only 1/10000, which can effectively avoid mutual interference and ignition failure with neighbors [Call Tone] offers 36 different call tone options, from melodies to a simple buzz. Customize your doorbell sound to your preferences whenever you want. With 4 levels of volume control, you'll never again have to miss the entrance of a visitor or customer. [Wireless] Wall installation without cables. Battery-operated wireless doorbell sensor and plug for quick and easy use. Number of shipments: 1 receiver and 1 sensor