Basic features: World public frequency: 2.4GHz data voice/image transmission Full-duplex voice speaker phone, voice is loud and clear Key wake-up call visit, standby power sleep Effective communication channels 83, any stable environment can call Improved automatic adaptive frequency-hopping (AFH) technology, super error correction Anti-jamming capability With CE, CCC, FCC and R-NTTE marks Short antenna design, beautiful new shape Other optional features: automatic image storage, photo-taking, battery-saving Super infrared night vision image control functions Performance indicators: Power supply: 5V DC (battery) Working current: 150mA work S/N ratio: voice >55dB Operating temperature: -40 to 70°C Communication distance: open to >300m (longer set according to customer's requirements)