Wireless digital doorbell Backing: 60pcs/CTN Sound selection: 3pcs of music: Dingdong; To Alice; London Iron Bridge golden music Receiver: AC power; Emitter: 12V battery (1pc) Backing Box: absorb plastic/ neuter, English color paper card Carton Size: Feature: when the music sound, 3 color of light flash with dance. Function: easy to fix, without cord; digital crystal, seldom Repeat in subsection; long distance of remote-150M; less energy.Trademark: wafon Model: HFD-8510CA Standard: CCC Productivity: 100,000pcs/m