* 4-wire system * Features 7″ screen indoor monitors * Video Monitoring, intercom, 2-way communication & door release buttons * Hands-free communication * Intercom between indoor monitors in the same apartment * Door stations with integrated access control * Expands to a maximum of 3 tenants * Supports up to 2 door stations & 4 indoor monitors per apartment * Monitor, answer & unlock your door from a smart phone/table