Panasonic Digital Wireless Headphones RP-WH5000S Digital infrared ray transmission system Decoder function - Dolby digital and Dolby professional logic II, DTS and MPEG-2 AAC Soft ear-pads that give you a total comfort around your ears Headphone playback frequency - 18 Hz - 22,000 Hz 3.75mHz sub-carrier frequency (up to 26 feet)