Item Type: Infrared Sensor Doorbell Material: ABS Transmitter Battery: AAA lithium battery x3 Package List 2 x Transmitter 1 x Receiver 2 x Connector 2 x Base 4 x Screw 4 x Expansion Bolt 1 x Instruction Manual 1Accurate Motion Detection: Equipped with a highly sensitive sensor, this infrared sensor doorbell can accurately detect every movement of a person. 2Intelligent Voice Prompt: Featuring smart voice alarm function, this doorbell provides friendly voice prompts when someone enters, enhancing the user experience. 3Wireless Connectivity: This infrared sensor doorbell utilizes wireless transmission technology, eliminating the need for complicated wiring and ensuring easy and convenient installation. 4Alarm Function: With built in alarm capabilities, this doorbell instantly triggers an alarm to alert store owners or employees when an abnormal situation occurs. 5Commercial Welcoming Device: Specifically designed for commercial environments, this infrared sensor doorbell can be widely used in shops, offices, and more.