The FM R37 features seek-button channel selection with access to 17 pre-set, wideband frequencies (72 to 76MHz). Offers sleep mode, low-battery indicator and stereo headphone jack. Compatible with all Williams Sound 72 to 76MHz wide-band transmitters. Digitally synthesized for exceptional audio clarity and stability. Versatile 3.5mm stereo/mono jack allows for a variety of earphone/headphone options, and is neckloop/telecoil-equipped hearing aid compatible.