OY713 Blcak Music Headset Wireless BT5.0 Headphones Call Center Earphone With Microphone 1.Multifunctional: Equipped with features of BT connection, TF card music playing, AUX-IN wired music playing, FM radio, earphone monitoring, and hands-free call with Microphone. 2.BT Connection: BT5.0 technology ensures stable and quick connection, easy to pair with almost all the BT-enabled audio devices, freely to enjoy wireless music and hands-free calls. 3.AUX-IN Function: When in power off status, connect to the audio devices (such as MP3MP4, Laptop, etc) without BT function via the 3.5mm audio cable (NOT included) to enjoy music. 4.Detachable Microphone: HD microphone reduces ambient noises and grasps the detail of voice. You can get high-quality hands-free phone conversation. Long press M key can mute mic. 5.Earphone Monitoring: Supports KTV mode. In this mode, you can read, recite or sing into the microphone, and the headphones pick up your voice, allowing you to immerse yourself in your own singing or revision. 6.Ergonomic Design: Adjustable headband length, foldable soft leather ear cushion, comfortable to wear, suitable for different head sizes, and easy for storage. 7.Long Battery Life: Built-in 300mAh rechargeable battery lasts up to 25 hours of music playing time per charge cycle (depending on music volume). Charging time is about 2 hours.