The plug-in chime will be activated when a visitor is pressing the smart doorbell. Plug-in chime is a practical tool that matches with smart doorbell, and they both provide home security for you 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 for selection, meeting various needs.A chime can pair with multiple doorbells, a doorbell can pair with multiple chimes.Note: Size and color may be slightly different due to manual measurement and different light conditons or other reasons, please in kind prevail. Thanks for understanding.Specifications:Color: Black/ White (Optional)Material: PlasticPlug: UKVoltage: AC 90~250VFrequency: 433MHzPower Consumption: 10mWVolume: adjustable, up to 110dBMusic Selection: SupportChime Size (plug not included): 73 * 73 * 32mm / 2.9 * 2.9 * 1.3inPackage Size: 8 * 8 * 5.5cm / 3.1 * 3.1 * 2.2inPackage Weight: 75g / 2.6ozPackage List:1 * Plug-in Chime1 * User Manual (English)