The FM 457 has the cutting-edge PPA T45 transmitter, with multiple digital audio input options and an OLED display with easy-to-manage menu navigation. Has three powerful microprocessors and the same high-quality audio and RF performance you’ve come to expect from Williams Sound. With an operating range of up to 1000 feet, the FM 457 is ideal for large venues where superior coverage is essential. This complete turnkey solution includes four R37 receivers, each featuring seek-button channel selection with access to 17 pre-set wideband frequencies between 72 to 76MHz. The system is expandable, accommodating any number of listeners. This system complies with 2010 ADA guidelines for hearing assistance and is covered by Lifetime PLUS limited warranty.