Usage Tips: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!<br> Features:<br> 433MHz frequency, compatible with wireless video doorbell.<br> Plug-in chime, easy to use, designed for indoor use only.<br> Adjustable volume, low to mute, up to 110dB.<br> Different melodies for selection, meeting various needs.<br> A chime can pair with multiple doorbells, a doorbell can pair with multiple chimes.<br> 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.<br> Specifications:<br> Color: Black/ White (Optional)<br> Material: Plastic<br> Plug: UK<br> Voltage: AC 90~250V<br> Frequency: 433MHz<br> Power Consumption: 10mW<br> Volume: adjustable, up to 110dB<br> Music Selection: Support<br> Chime Size (plug not included): 73 * 73 * 32mm / 2.9 * 2.9 * 1.3in<br> Package Size: 8 * 8 * 5.5cm / 3.1 * 3.1 * 2.2in<br> Package Weight: 75g / 2.6oz<br> Package List:<br> 1 * Plug-in Chime<br> 1 * User Manual (English)