1.220V doorbell push switch 2.Install outside wall,show room number, ... Two kinds-Input Voltage-220V Item : doorbell push switchThere are 2 Kinds1.Low voltage 12V doorbell switch :Match wih other system to ... so on).Input voltage is 12V.2.High voltage 220V doorbell switch :Use alone,direct connect to 220V Live wire(Power ... ,Make up room,Please wait a moment.2. With doorbell button3. Blue background light