Aiphone TD-12H 12-Call Master StationThe Aiphone TD-12H is a 12-call handset master station. It can work with up to 12 Sub Stations and up to two of those can be door stations. The color of this item is whiteFeatures?Multi-channel, selective calling handset-type system?Wall or desk mountable ?Up to 2 door stations (audio or audio/video), with selective door release?Optional paging zones, with or without talkback.