XT11 Magnetic In-ear Wireless Bluetooth Earphones. Extra Bass Bluetooth Wireless Earphones Earbuds Sports Stereo Headset With Built In Mic. 100% Brand New And High Quality. Exclusive Design, Ergonomic And Comfortable To Wear.    In-ear Mould Which Is Designed To Provide The Best Bass. Built-in High Sensitivity Microphone, Clearer Voice Quality. Compatible With Any Bluetooth Device.   Specification   Bluetooth V4.2 Frequency Response: 90Hz-20KHz Signal To Noise Ratio:  ≥85dB Working Time Up To 2.5 Hours With Average Volume Charge Time: 1 Hour Battery Type: 50mAh Lithium Battery Box Contents   1 XT11 Bluetooth Earphone Charge Cable Manual Book