... function,5. Luminous button for night vision, 7. LED display,8. Password unlock functions. Technical Parameter :1. ≥500 TVL images resolution ... . Networking connection RS-485,5. Quiescent current 50 mA; 6. Calls for about two minutes; 7. Temperature -10~+55°C,8. R.H ... manufacturer producing door bell and door phone with more than 8 years' experience.2. Our products quality utmost, price competetive.3 ...