The Sennheiser HDI 830 is 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 provides excellent speech intelligibility and very good music reproduction. It is comfortable to wear and is sure to provide long operating times.