Looking for professional, yet wireless earphone? Searching of sturdy, trustworthy wireless earphone that can give you a wonderful listening ? , ! Our wireless in-ear earphone set must meet your needs. Features -Color: Black -Material: ABS -Size: 6.00X4.20X1.70cm/2.36X1.65X0.67in - , transmission of the sound is more stable and quick. - Wonderful listening effect, clear and vivid to listen. - Our earphones can be single or double, according to your will. - Enhanced sound transmission, faster pairing, more stable wireless connection and wider compatibility. - Wireless design, no more worry about tangling or messy. Specifications Transmission distance: outdoor straight line distance of 15 meters Headphone battery capacity: 30mAh Charging bin battery capacity: 400mAh Speakers: 10mm speakers Listening time: 3.5 hours Talk time: about 4 hours Standby time: 120 hours Charging time: 50 minutes Operating current: 5-10mA Operating voltage: 3. -4.2V Distortion: < 0.1% Signal-to-noise ratio: > 90dB Frequency corresponding: 20-20KHz Transmitted power: 4 Horn impedance: 32 Carrier frequency: 2.4 GHz Package list: 1 x pair of Earphone 1 x Charging warehouse 1 x USB cable 1 x instruction book