Description:2-Way Talk Back: Wireless voice doorbell, talk with visitor via two-way voice intercom,know who visit your house,it’s more safe.Easy Installation: The doorbell can be fixed on the wall with the use of adhesive stickers. You can place it in the bedroom, kitchen, living room, study room, everywhere you want.Portable Interphone: The door chime is featured with exquisite size, metallic-feeling housing and loud volume. Outdoor-bell pair with indoor-bell by learning its unique code, 1 outdoor-bell can paired with N indoor-bells and no interference each other. This package includes 1 outdoor bell and 3 indoor bell.Low Power Consumption: The outdoor-bell is power supplied by 4pcs alkaline battery(not included), indoor-bell is power supplied by rechargeable Li-ion battery. Low power consumption, long standby time for outdoor-bell lasts 6 months.How it Work: Visitor press the outside doorbell, after got ring,you should press the button one time on receiver to get connected and then hold to speak,release it after finished.Specifications:Material: plastic.Color: show as pictures.Idoor-bell:Power supply: built-in rechargeable Li-ion battery.Transmission distance: 50-100m(without any obstacle).Work time: 48 hours.Wireless frequency: 467.6375mHz.Working temperature: -20+55 degree Celsius.Outdoor-bell:Power supply: 4 x AAA Battery(not included).Transmission distance: 300m (without any obstacle).Work time: 6 months.Wireless frequency: 467.6375mHz.Working temperature: -20 +55 degree Celsius.Product size: approx. 100*60*15mm/3.93*2.36*0.59”.Notes: Due to the light and screen setting difference, the item’s color may be slightly different from the pictures.Please allow slight dimension difference due to different manual measurement.Package include: 1 * Outdoor Bell.3 * Indoor Bell.1 * Data Cable.