Pyle PLVWH3 In-Car Dual-Channel Wireless Stereo Headphones Compatible with In-Vehicle AV Applications (Discontinued by Manufacturer) Light Weight Design For Comfortable Wearing - A Channel: Right Channel: 2.8mhz; Left Channel: 2.3mhz - S/N Ratio: 70db(Minimum) Auto Mute On Headphone - B Channel: Right Channel: 3.8mhz; Left Channel: 3.2mhz - Channel Separation: 40db(Minimum) Auto Power Off Function On Headphone - Speaker: 30mm Mylar - Frequency Response: 30-20000Hz Personal Volume Control - Cone Impedance: About 32ohm - Power Supply: 2AAA Battery Dual Channel - Effective Range(Maximum): About 10 Meters - Battery Life: About 48 Hours