When visitor press doorbell,notification will sent to your cellphone,you can answer it and enter video call interface,supports maximum share to 10 family members. Auto capture at the same time and save image in cloud,you can review visiting records in app. Voice change Function with a man voice at home ,children and women get safer when alone. Easy installation paster or screw fixed,3M sticker paste or physically screw fixed two way installation. Long time standby up to 365 days. High Definition night vision,infrared night vision function,auto switch day/night. Built-in 38 melodies for your options,adjustable volume. Built-in battery. Packing List: 1 x Doorbell Machine 1 x Indoor Ding-dong Machine 1 x Charging Cable