... system with PLUG & PLAY connection.Up to 4 door stations and 4 indoor phones.Intercom between indoor phones.Calling transfer between ... phones.E-lock can be connected to both door station and indoor phone.Anti-vandal, waterproof, cast aluminium, surface mount.Night ... phonesVI,V22VI,V21,V23VI,V12,V18 Video door station with CE and RoHS certification