Power Source Transformer or adaptor ( AC 110V --240V ) Assurance_temperature -40~+ 50oC Camera 1/3 Lens 3.6 Min Illumination 0.1 Lux Monitor CM-06DNRM Max_Wiring Distance RVV4x0.5 multi-core copper wire for transmission distance within 50m, RVV2x0.5 multi-core copper wire and 75-5 video wire for up to 200m Tv System PAL OR NTSC Ring Bell Double Ding-Dong Ring Wiring 4 wires in polarity. ( include Monitor and GND ) Call Function Call between monitors is available Extension Up to 4 monitors with 1 door station is possible Door Release function Signal Unlocking LED You can enjoy a constant clear & bright picture on the screen at any light level Specification 1. One entry door station supports four indoor phones 2. Audio indoor phone WL-06DFH compatible 3. Handset dual talking, supervising, intercom and remote unlocking 4. Functions upgraded if needed (picture-memory) satisfying users demand 4. B/W or color available5.Pin hole door station and surface mounting design.