Item Type: Motion Sensor Doorbell Material: ABS Transmitter Battery: AAA lithium battery x3 Package List 1 x Transmitter 2 x Receiver 1 x Connector 1 x Base 2 x Screw 2 x Expansion Bolt 1 x Instruction Manual 1Responsive: Sensor doorbells respond in time to avoid missing any visitors, small size, easy installation, let you respond to the doorbell in time. 2Voice Prompts: When entering the door, the doorbell emits a clear, loud voice reminder to provide a warm welcome service. 3Wireless Connection: No complicated wiring installation, convenient and fast, reduce unnecessary trouble. 4Split Install: The equipment is split and can be installed in different locations of the store more flexibly to provide all round security protection. 5Commercial Use: Specially designed for commercial places, such as stores, companies, etc., to meet the daily doorbell and safety management needs.