Advanced 100% digital technology with this Baby Monitor,WiFi Free,Digital signal for crystal clear clarity ... adaptor or 4.2V Li-ion battery1.1.1. Baby (Transmit) unit- Integrated CMOS active-pixel image sensor ... DC adaptor or 4.2V Li-ion battery- 2. Baby Monitor Operation Specification2.1. Features* 100% Digital Technology* Digital signal ... 8 cameras, Auto, manual scan 2.4Ghz Digital Video Baby Monitor