Bingle B616 Wireless FM Radio Headphone TV Headset Multifunction Stereo Wireless Headphones Microphone FM PC TV Phone Earphone Features: 1. Wireless TV connection, the effective distance is 20 meters to 30 meters. 2. Wire connect 3.5MM audio interfaces devices such as CD, TV, computers, mobile phones etc .. 3. Built-in FM radio headphones, listening to the radio anytime, anywhere. 4. NdFeB pronunciation unit and high-quality gold-plated pin headphone components, pristine sound quality. Specifications: style: Wrieless, 3.5mm Speaker Dimension: Φ40mm Impedance: 32Ω ± 15% Frequency Response: 10Hz-20KHz Sensitivity: 92 ± 3dB at 1KHz Wrieless Headphone Voltage: 2.0 ~ 3.0V, 2 * AAA Electric current: 40mA Wireless Headphone Receiving Frequency: 109Mhz / 110Mhz Radio frequency: 87.5 ~ 108.0MHZ Receiving frequency response: 20 ~ 20KHz S / N rate:> 60dB Transmitters Voltage: 2.0 ~ 3.0VDC, 2 * AAA Electric current: 40mA Transmitting Frequency: 109Mhz / 110Mhz Work distance in vast place: 20M ~ 30M Note: Dear friend, the Microphone is bulit-in Trasmitter, not bulit-in Headphone