Features:BT 5.0 technology: Lower power consumption and more stable signal transmission.A READABLE TF card Supported (NOT included): Support BT and MP3 local playback.Made of TPE material: Skin-friendly and soft, waterproof and sweat proof, without fear of sweat and rain.Ergonomic design, smooth lines, fit the human body: Stable and comfortable, crazy can not be shaken off.Super light, foldable, elastic and automatic shrink: Easy to carry and no knots.Built-in HD noise reduction microphone: Support to answer/reject calls, transmit clear and natural sound.Specification:Model: A-23Color:GRAY , white, red, blue(optional)Connection: BT5.0Effective distance: 10mHeadphone sound quality: heavy bassHeadphone material: ABS + PCSpeaker unit: 27mm speaker impedance is 32 ohmsEndurance Headphone battery: 450mAhMusic playback time: about 10 hoursHeadphone charging time: about 1-2 hoursPackage size: 14.8*10.3*3.8cm/5.82*4.05*1.49inPackage weight: 138g/4.86ozNote: The above data comes from our laboratory test. There may be some errors depending on the application!Package List:1 * Headphone1 * User Guide1 * Charging Cable