Detailed Product Description Video door phone, door phone, video intercomModel: CR454Features: 1) Handfree intercom2) Display visitor3) Door remote unlocking4) Adjust contrast & brightness5) Supervise door situation anytime6) Communication between the monitors7) Up to 4 monitor to 1 camera (4M: 1C, 3M:1C, 2M:1C, 1M:1C, 2C:1M)Specifications:1) Model: CR4542) Power supply: DV15V, AC100~250V3) LCD ...