Feature: 1. Wide Use: Wireless doorbell has a wide range of applications and is suitable for hotels, restaurants, guest houses, homes, office buildings, and conference rooms. 2. Highly Sensitive: The wireless doorbell responds quickly and allows the elderly to press the button easily even though they use light strength. 3. Intelligent Music: The doorbell has a wide range of music built in to give you a pleasant listening experience. 4. Durable Construction: Smart home doorbell is made of premium ABS, which is hardness, sturdy and durable and has a long service life. 5. Easy Installation: Doorbell ringer wireless is designed to be easy to install. With the simple installation steps, you can mount the doorbell in your preferred position. Specification: Item Type: Wireless DoorbellMaterial: ABSModel: M525+F51 Receiving Frequency: 433MHZ Transmitting Distance: 150m (in the open) Operating Power: 0.5W Music: 32 songs Plug: US standard plug Input Voltage: 100 to 220V Battery Type: Button Cell Battery Type: 12V 23A Battery Capacity: 80mAh (shipped with built in battery) Uses: For hotels, restaurants, guest houses, homes, office buildings, conference rooms. Package List: 1 x Doorbell Button1 x Doorbell Host1 x Gasket2 x Screws2 x Expansion Screw1 x Instruction Manual