Ergonomic small-size design, secure & stable fit. BT 5.3, low power consumption stable transmission, audio and picture sync-up without delay. Bio-fiber diaphragm dynamic speaker, HiFi super bass quality . In-ear passive noise cancellation technology, blocks noise immediately once putting on the earbuds . Dual main earbud mode, seamless switch between single and double earbuds, instant connection once taking out the earbuds . Single earbud play time reaches up to 48h with a charging case.