switching between primary and secondary. pop-up window. Use the tap function. intelligent induction. noise cancellation that is active. HIFI has a clear voice. Lanyard and silicone case. The GB/T14471-2013 standard The earphone In-ear fit Details: Lightning Version 5.2 of the wireless connection protocol Distance: at least 10 meters Frequency of transmission: 2.4GHz–2.48GHz 33mAh is the battery's capacity. 180-hour standby time 250mAh is the charging case's battery capacity. About six hours of music Talking time: roughly five hours About two hours for USB charging