Optical Fiber Bluetooth Receiving Transmitter.1 Audio Adapter Digital To Analog Microphone Singing Features: The product has beautiful appearance, exclusive private Design, factory private Design, and patented design. Designed with Bluetooth.1 chip, it has stability. Bluetooth reception and Bluetooth transmission (TX) are combined. Equipped with high-definition LED digital display screen, the working status and Bluetooth mode are clearly visible. Built-in DSP decoding chip, heavy and low sound effect, support three-gear gain Changeable. The NFC function is upgraded, and the mobile phone senses feel and feel . Controllable indicator, soft and not dazzling, and the brightness will increase/decrease with the volume. Built-in 1200mAh rechargeable lithium battery, continuous listening to music for about 8 hours, battery life up to 30 days Support U disk/TF card playback and transmission, and support MP3/WMA/SBC/WAV/DTS/A52/FLAC/AAC/AIF/AMR/APP format. It supports various operations such as 5~8 meters red and private model external remote control, mode/signal/volume/up/down/mix/microphone. Built-in 6.5mm high-definition microphone, supporting microphone access and singing, and built-in anti-howling design. The product connection is easy, without any driver and the cumbersome downloading of APP; Specification: Material: abs Size: About 6.7x9.8x2.4cm/2.6x3.9x0.9in Bluetooth version Bluetooth V5.1 Support protocol A2DP/AVRCP/HFP/SBC Operating frequency band 2.402GHz - 2.480GHz Power class Power class 2 (Class II) Sensitivity - 85dBm