Williams AV FM 557 FM+ FM & Wi-Fi Assistive Listening System (4 Receivers)The Williams Sound FM+ FM & Wi Fi Assistive Listening System is a turnkey system designed to help individuals needing auditory assistance or language interpretation. It helps such users overcome background noise, reverberation, and distance from the sound source. This system includes an FM T55 transmitter, which supports both FM and Wi Fi, and works with both iOS and Android WaveCAST apps. Also included are four PPA R37N bodypack receivers, each