... 4) Digital function Products name: Wireless video door phone/Digital video door phone 616 Advantages: 1) Wireless video door phone 2) 3.5" ... high degree of confidentiality;4) Use full-duplex mode intercom calls, voice clarity5) Hands-free calling function;6) ... Instructions9) It with menu features. indoor and outdoor voice, intercom size, brightness, contrast, regulation of calendar time are adjustable, ...