Sennheiser SET830-TV Wireless Infrared Stereo Assisted Listening System Outstanding customised stereo sound Three selectable hearing settings on the transmitter: optimised speech intelligibility thanks to switchable compression and treble emphasis Treble emphasis can be individually set Cordless mobility of up to 12 m within a room thanks to the infra-red transmission Large, ergonomically shaped volume control and balance control on the receiver Perfectly fitting and flexible earpads ensure maximum wearing comfort Receiver switches on and off automatically Receiver can be placed on the transmitter's charger facing in either direction LEDs provide visual signals of individual control processes Lithium polymer battery technology ensures a long operating time of up to 12 hours. Kindly refer for user manual for usage instructions