Sennheiser RS 175, Wireless Headphones, Rechargeable wireless headphones, Up to 100 m range, Adjustable dynamic bass boost and two surround sound modes for sound customisation, Supports connection to analogue and digital audio sources and allows switching between the audio inputs, Multipurpose transmitter serves as a charging and docking station, Multi-receiver transmission of the transmitter supports up to 2 headphones simultaneously, Circumaural, Closed design, Max. SPL: 114 dB SPL, Frequency response: 17 - 22,000 Hz, Up to 18 hours of operation, Weight 310 g, Includes HDR 175 headphones, TR 175 radio transmitter, optical cable, audio cable (analogue), power adapter with 4 country adapters (EU, UK, US & AU), 2 AAA-LSD NiMH batteries