The plug-in chime will be active when a visitor presses the smart doorbell. The plug-in chime is a practical tool that matches the smart doorbell, and they both provide security for your home! Features: 433MHz frequency, compatible with wireless video doorbell. Plug-in chime, easy to use, designed for indoor use only. Adjustable volume, low to mute, up to 110dB. Different melodies to select, meeting various needs. One chime can pair with multiple doorbells, one doorbell can pair with multiple chimes. Note: The size and color may be slightly different due to manual measurement and different light conditions or other reasons, please in kind prevail. Thank you for your understanding. Specifications: Color: Black / White (optional) Material: Plastic Plug: EU Voltage: AC 90~250V Frequency: 433MHz Power Consumption: 10mW Volume: Adjustable, up to 110dB Music Selection: Support Chime Size(plug not included): 82 * 82 * 20mm / 3.2 * 3.2 * 0.8in Package Size: 9.5 * 9.5 * 7cm / 3.7 * 3.7 * 2.8in