The RS 180 wireless headphones from Sennheiser allow you to enjoy full uncompressed CD-quality audio without the hassles of wires. The system includes a pair of around-ear headphones and a base station transmitter that lets you enjoy your audio. The transmitter connects to your CD player, computer, home theater, or other audio devices. It uses KLEER wireless technology to send uncompressed digital audio up to 320' to the headphones. KLEER technology provides automatic, interference-free pairing between the transmitter and the headphones, so there's no need for tuning. The transmitter also acts as a dock and charging station for the headphones. 

Technical Specifications~ 

System requirements 
Modulation: zMSK Digital 
Carrier frequencies: 2.4 - 2.48 GHz 
Range: approx. 100 m in the open area 
Transmitter 
Audio input: 3.5 mm stereo 
Audio output: RCA 
Power consumption: < 0.5 W 
Power supply: 5 V DC , 500 mA 
Signal-to-noise ratio: 85 dBA (0.5 Vrms, 1kHz) 85 dBA (0.5 Vrms, 1kHz) 
Weight: approx. 204 g (without batteries) 
Dimensions: 12.5 cm x 11.2 cm x 23.0 cm 
Headphone 
Transducer principle (Headphones): open, dynamic 
Ear coupling: circumaural 
Sound pressure level (SPL): 110 dB 
THD, total harmonic distortion: <0.5 % a 1 kHz, 100 dB SPL 
Frequency response: 18 Hz - 21000 Hz 
Impedance: 32 ? 32 ? 
Charging time: approx. 16 hours 
Power supply: 2 NiMH-Akkus Typ AAA, 1,2 V, 600 mAh 
Operating time: approx. 24 hours 
Weight: approx. 204 g (without batteries) 

Package Content~ 

Sennheiser RS 180 Headphones 
HDR 180 headphone (receiver) 
TX 180 transmitter 
Multi-country charger 
Detachable audio cable 
RCA cable 
3.5 / 6.3mm adapter 
2 x AAA NiMH rechargeable batteries 
Instruction manuals