Adjustable Door Chime provides a perfect solution for avoiding being . With 4 levels of adjustable volume and a battery, it can reach within 150m in open and unobstructed places, making it ideal for homes.<br><br>Name:Smart Door Bells Signal frequency:433Mhz MAX volume:110 decibels Voltage: 110V-220V (two plugs) Ringtone:61 types Power consumption:0.25W Supporting Battery:23A battery (standard battery) Plug Type:US Plug, it applies to Canada, India, Mexico, Thailand, Taiwan, the , the Philippines and so on. Colour:White Material:ABS<br><br>Package Contents: 1 * Wireless Door Chime 1 * Speaker<br><br>Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.