One-button ringing:Smart wireless doorbell, 4-level adjustable volume, even if used in complex house types, the penetrating power of the ringing sound can let you know that someone is visiting. High volume metalloudspeaker:Honeycomb sound cavity design, make the ringtone more pleasant,The ringing sound covers an area of about 300m. Product features 1: 300mf signal coverage 2: 4-level adjustable volume 3: Loud ringing sound 4: Free matching 5: Intelligent power-off memory 6: 32 music melodies 7: Plug and play 8: Strong signal penetration 9: Easy to Plug Type: EU Plug,it applies to Indonesia, Germany, France, Spain, Italy and so on. Voltage: AC220V Colour:Black Material:Plastic Package Contents: 1x Doorbell 1x Button 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.