Sennheiser Wireless Headphone RS175

Headphone system with superior bass and surround modes for pure entertainment. 
Closed, circumaural headphones with excellent digital wireless audio transmission
Exceptional digital audio clarity and transmission range of up to 328ft/100m (line of sight)
Enables switching between dynamic bass and virtual surround sound
listening modes for situational sound customization
Supports analog and digital audio inputs and allows toggling between the inputs
Intelligently designed controls for maximum ease of use
Multi-purpose transmitter – also functions as ‘easy-charge’ cradle and docking station
Multi-receiver transmission – transmitter supports up to two pairs of headphones simultaneously
Ergonomic design for enhanced wearing comfort
2-year warranty

What's in the Box?
HDR 175 headphones
TR 175 transmitter
Optical cable
Audio cable
Power supply with 4 adapters (EU, UK, US & AU)

Specifications
Headphones
Frequency response 17 - 22,000 Hz 
Max. sound pressure level 114 dB at 1kHz, 3% THD 
THD, total harmonic distortion <0.5 % at 1 kHz, 100 dB SPL 
Transducer principle dynamic, closed 
Weight 310 g (incl. batteries) 
Operating time up to 18 hrs 
Transmitter
Audio input 1 x 3.5 mm stereo, 1 x optical digital 
Power consumption ≤ 0.3 W (standby) 
System
Range Up to 100 m 
Signal-to-noise ratio Analog input: typ. 85 dBA at 1 Vrms 
Signal-to-noise ratio Digital input: > 90 dBA 
Modulation 8-FSK Digital 
Carrier frequencies 2.4 – 2.48 GHz