Williams AV FM T55C D FM+ C Assistive Listening System with DanteFM+ C with Dante is the first transmitter of its kind to offer an FM broadcast and Wi Fi audio broadcast from a single input source. Whether using the FM+ C for assistive listening, language interpretation, or audio description, this dual broadcast technology gives users the option of listening to real time audio stream on their smartphone or tablet using the free WaveCAST receiver app (iOS and Android) or use an available FM receiver from the venue.