The TF-iL Tour Guide Induction Loop is an amazingly simple but life changing accesory for the hearing impaired. Turn the tour guide. Sytem into a a device where a transmitter can pick up a speaker, announcer or family member then send that to a single or many receiver body packs used by the hard of hearing client , plug in the neck worn induction loop and the client can then use their own hearing aids to hear the conversations and announcers. perfect where induction loops permanant installation is not possible.