The Sennheiser HDI 830 feature a professional two-channel stethoset receiver for wideband transmission systems (with carrier frequencies of 2.3 MHz and 2.8 MHz) in museums, theaters, and churches. The wearer can switch between channel 1, channel 2, or stereo signal reception. The receiver gives excellent speech intelligibility and very good music reproduction. It is comfortable to wear and is sure to provide long operating times.