... camera door phone, color indoor phone system, video door phone for indoor unit,color indoor phone, intercom system indoor phone, ... color video indoor phone, digital indoor phone, color indoor phone for apartment, B/W handfree indoor phone, video door phone (indoor ... Degree of distortion:≤5%.8.16-chord ring, 30seconds for ringing.9.Time for display: 60 seconds. 10.Function: video intercom, long-distance ...