... ,by key 3: handfree,night vision 4: ultrathin monitor 2V2 intercom system V7I-K1: 7inch color TFT video door phone 2: unlock ... monitors.(different choice)**four wires,DIY installation**Including in one kit:One indoor monitor, one outdoor camera, power adapter, user manual ... <0.5W working <10W **Relative humidity: 10 % - 90%(RH) 2V2 intercom system V7I-K