White Calls/Music In-ear Headset True Wireless Stereo (TWS) Bluetooth 5.2 Intraaural Microphone type: Built-in Built-in battery Lithium Polymer (LiPo) 30 mAh Comfortably Better MusicHUAWEI FreeBuds 4 takes Open-fit Active Noise Cancellation to new heights, incorporating all-new adaptive ear-matching technology for even greater audio immersion. The open-fit design allows air pressure to stay equalised, while ensuring important environmental sounds can still be heardfor a safer, more comfortable wearing experience even after long hours of use.In Tune with YouEvery ear is different. That's why HUAWEI FreeBuds 4 uses adaptive ear-matching technology to detect your unique in-ear shape and how you wear the earbuds, then intelligently selects from a variety of noise cancellation modes to achieve optimal low-frequency sound reduction.A New Sphere of ListeningThe perfect-circle charging case is designed to fit right in your palm. And now even smaller and lighter, it slips seamlessly into you