Sennheiser Remanufactured RS 140 Wireless Balanced Headphones (Discontinued by Manufacturer) Wireless, rechargeable hi-fi headphones with switchable dynamic compression system and left/right balance control Intelligent auto tuning and automatic signal control ensure high-quality reception Transmission range of up to 150 meters; 18 Hz to 21 kHz frequency response Lightweight, comfortable design; 23 hours average battery life per charge Remanufactured to like-new condition; 90-day warranty