Product Features: No installation and debugging required, ready to use immediately upon receipt. Built in noise reduction chip, environmental noise. One click activation of intelligent noise reduction can better reduce the impact of environmental noise and provide you with pÃre sound quality enjoyment. It is Built-in a large-capacity built-in battery and features the function of being used while charging, which can meet the need for long-term use. Specifications: Analog audio output: /RT, stereo Dynamic range 1kHz: ≥ 105dB Crosstalk: ≥ -106dB Signal to noise ratio: ≥ 85dB Bit rate: 44.1KHZ/16bit Earphone output power: 25mW Frequency response: 20Hz-20KHz Color: Black Material: ABS Package Contents: 1 x Sound Card 1 x charging cable 2 x audio cables Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.